NPHY 111 EC BASIC PHYSICS I Faculty of Natural and Agricultural Sciences Study guide compiled by: Mrs H. Vosloo Copyright © 2020 edition. Review date 2020. North-West University No part of this study guide may be reproduced in any form or in any way without the written permission of the publishers. It all starts here • • Ranked in the top 5% of universities globally by the QS-rankings Contributes the second largest number of graduates annually to the labour market Dit begin alles hier • • As een van die top 5% universiteite wêreldwyd deur die QS-ranglys aangewys Lewer jaarliks die tweede meeste graduandi aan die arbeidsmark Gotlhe go simolola fano • • Re beilwe mo gare ga diyunibesiti tse 5% tse di kwa godimo go ya ka peo ya maemo ya QS Ngwaga le ngwaga go abelwa palo ya bobedi ka bogolo ya badiri mo maketeng ya badiri MODULE CONTENTS Module information ................................................................................................................iii Welcome ................................................................................................................................iii Module outcomes...................................................................................................................iii Prerequisite............................................................................................................................iv Contents of this module .........................................................................................................iv Time schedule .......................................................................................................................iv General module information and contact details ....................................................................iv Study material ........................................................................................................................vi Working method in physics and how to study.........................................................................vi Assessment ........................................................................................................................... x Priorities ................................................................................................................................xii Action words ........................................................................................................................ xiii Before we start – a bit of inspiration: .................................................................................... xiv Icons ....................................................................................................................................xiv Warning against plagiarism ...................................................................................................xv Study division A: Kinematics and vectors ............................................................................... 1 Study unit 1 Measurement ........................................................................................ 1 Study unit 2 Motion along a straight line ................................................................. 3 Study unit 3 Vectors.................................................................................................. 6 Study unit 4 Motion in two and three dimensions .................................................. 9 Study division B: Dynamics .............................................................................................. 12 Study unit 5 Force and motion I ............................................................................. 12 Study unit 6 Force and motion ii ............................................................................ 15 Study unit 7 Kinetic energy and work .................................................................... 17 Study unit 8 Potential energy and conservation of energy .................................. 20 Study unit 9 Centre of mass and linear momentum ............................................. 23 Study unit 10 Rotation .............................................................................................. 26 Study unit 11 Rolling, torque andangular momentum ............................................ 29 Study division C: Statics ................................................................................................... 32 Study unit 12 Equilibrium ......................................................................................... 32 Study unit 13 Gravitation .......................................................................................... 34 Study division D: Hydrostatics and hydrodynamics ....................................................... 36 Study unit 14 Fluids .................................................................................................. 36 Study division E: Periodic motion and waves ................................................................ 39 Study unit 15 Oscillations......................................................................................... 39 i Study unit 16 Waves ................................................................................................. 42 Study unit 17 Waves ii .............................................................................................. 45 Study division F: Study of heat......................................................................................... 48 Study unit 18 Temperature, heat and the first law of thermodynamics ................. 48 Study unit 19 The kinetic theory of gases ............................................................... 51 Study unit 20 Entropy and the second law of thermodynamics ............................ 54 List of the most important key words .................................................................................... 56 Meertalige kernkonsepte / Multilingual key concepts / Dikakanyokgolo ................................ 61 ii Module information Module code NPHY 111 Module credits 12 Module name Basic Physics I Name of lecturer(s) Mr. Ruhann Steyn (PC) Dr. Donald Ngobeni (MC) Office telephone Email address Ruhann.Steyn@nwu.ac.za (PC) Donald.Ngobeni@nwu.ac.za (MC) Building and Office no. G5-124 (PC) ..............(MC) Consulting hours By appointment only Welcome The subject-group Physics welcomes you to the module NPHY111. This module will equip you with the basic knowledge and understanding about physical phenomena that you will meet in everyday life and that you will need for your further studies. This module is also a preparation for students intending to continue with Physics as one of their major subjects. Module outcomes After completion of the module NPHY111, the student should demonstrate: • • • • • Formal mathematical knowledge and informed understanding of the fundamental concepts underpinning the subthemes of physics, i.e., kinematics, Newtonian laws of motion, work and energy, momentum, rotation and rolling, equilibrium, gravity, fluid mechanics, simple harmonic motion, waves, the study of heat, and thermodynamics. An awareness of the development of physical measurements and theories that shaped the progress of physics; The ability and skills to explain certain parts of the theory by means of the basic differential and integral calculus; to solve a variety of natural science problems in the above-mentioned subthemes and to evaluate the answers and apply them to phenomena within a well-defined and familiar environment. Effective utilisation of basic research skills, such as conducting experiments, measuring basic observable quantities related to special and controlled cases of natural processes, and processing these data. The ability to reliably communicate these discipline-specific ideas by writing a report in an accurate and coherent way while showing respect for conventions related to copyright and plagiarism. The ability to manage his or her learning and implement the discipline-specific learning strategies given in the NPHY111 study guide to address learning problems. iii • The ability to work in a group and make appropriate contributions and sharing resources to successfully complete the practical sessions and thereby taking coresponsibility for the attainment of the outcomes by the group. Conduct in the academic environment that adheres to the rules as stipulated by the North-West University code of conduct. • Prerequisite University Admission (with Mathematics and Physical Sciences) It is preferable that you should already have completed school level science successfully, since there are some parts of study units that suppose Physics school knowledge as background knowledge. Furthermore, we depend upon the algebra knowledge you acquired at school. Contents of this module A brief summary of the contents of this module is given below. The approximate number of periods to be spent on each of the study divisions is also provided. Study division Number of hours % of module A KINEMATICS 6 ± 15 B DYNAMICS 13 ± 35 C STATICS 4 ± 10 D HYDROSTATICS AND HYDRODYNAMICS 4 ± 10 E PERIODIC MOTION AND WAVES 6 ± 15 F STUDY OF HEAT 6 ± 15 You will find that you have already encountered at high school some of the work that we are going to do. We are repeating it in order to ensure a firm and uniform basis on which we can continue to work. The STUDY UNITS of this module have been divided according to the chapters in the prescribed textbook and the STUDY SECTIONS correspond with the paragraphs in the textbook. We will strictly adhere to this order. Time schedule This module consists of 12 credits that are the equivalent of 120 hours of study. The lectures periods and the study hour (self-study) are indicated with each Study Unit. General module information and contact details Consultation hours Please make an appointment if necessary. Potchefstroom campus: Make enquiries at G5-116 if the lecturer is not in his office. All arrangements about the practical work can be obtained from Mr. Moerdyk, G5-308. iv Mafikeng campus: …………………………………………………………………………...................................... ........................................................................................................................................... Lectures Monday: ______________________________________________________________ Tuesday: ______________________________________________________________ Wednesday: ___________________________________________________________ Thursday: _____________________________________________________________ Friday:________________________________________________________________ Study facilitator _____________________________________________________________________ Some successful and capable senior undergraduate or post-graduate students have been appointed as facilitators. They have been thoroughly trained in the techniques of study facilitation in order to assist you in mastering the strategy for study and in achieving the desired outcomes of your subjects. The section on “Study techniques” in this Study Guide gives more information about this system of facilitation. We shall introduce the facilitator for NPHY111 to you at the earliest opportunity. Tutorial period We will arrange for a few tutorial sessions to ensure that every one has the opportunity to ask their questions. The tutorial sessions offers you another golden opportunity to ask questions if there should be anything that you do not understand, as well as an opportunity to do additional exercises and solve problems with the required guidance and assistance. Keep in mind that every test and examination paper will also include a number of problems and applications. Semester test During assessment week: ________________________________________________ Autumn recess _____________________________________________________________________ _____________________________________________________________________ Final ending of lectures _____________________________________________________________________ _____________________________________________________________________ Examination You will write one paper of 3 hours. Duration examination): of examination (first v _____________________________________________________________________ _____________________________________________________________________ Duration of examination (second examination): ________________________________ Examination date: _______________________________________________________ Study material Prescribed textbook Printed: Halliday, Resnick and Walker: Principles of Physics. 10th Edition 2014 Online: The online edition of this textbook on WileyPlus will/can be incorporated. NB NB NB: Please consult your lecturer during the first lecture about which textbook (online or printed) will be used and to what extent. It will not be necessary to buy both, the online and printed form of this textbook is EXACTLY the same, therefore consult with your lecturer before making any purchase. Study guide The purpose of the study guide for NPHY111 is to guide you through your study, use it! Working method in physics and how to study General Outcomes: The main aim of this module is to equip you with the knowledge about physical phenomena that you will meet in everyday life and that you will need in further studies. We trust that you will develop an understanding of them. The module also aims to prepare you for further studies in Physics. We shall pursue the following outcomes in particular: • • • vi Insight or understanding: Understanding the work is important. One understands work if you can answer the why question about everything. Why is a definition defined like this and not in any other way? How does step 2 follow from step 1? Insight is to understand which steps are necessary for a certain derivation, and why only those steps will do. When one struggles to solve problems, the reason is usually that one does not yet know and understand the work. Accuracy: In Physics something is not “almost right”, for then it is “totally wrong”. You have to learn to get the precisely correct formulation for a definition, a law, or whatever. Communication: It is important to learn to express yourself logically and clearly in good English (or Afrikaans). Poor grammar and language will be penalized in tests or in the examination. Language remains the medium through which you communicate with your colleagues. In this course, you are required to associate a concept, an object, an idea or an action with a specific word. Since English is evolving on a daily basis, it is necessary that it should also be developing as a technical language owing to the addition of new terminology. One should strive always to let a technical term have one meaning only by associating it with a particular concept. The term needs to be appropriate, descriptive and typical of the concept, object, idea or action concerned. You should therefore pay careful attention to the way in which the lecturer uses the terminology and make certain that you do likewise. You should then never experience problems with regard to the understanding and communication of the relevant technical terminology. Mathematical symbols and formulae: Measured results based on what has been observed in nature are summed up in physics as mathematical formulae so that these provide a compact reproduction of the mutual relationships that are implied in the measurements. Theoretic models are then formulated for the measurements. Quantities therefore need to be defined in order that we may all know what we are measuring. Quantities are represented by a mathematical symbol that has content and meaning in physics. It is therefore always essential that you should clearly define the symbols that you use otherwise these will amount to mere mathematical manipulations. Describing nature by making use of defined mathematical symbols, formulae or equations therefore forms a powerful communication method in physics. Take care that you always explain or record the meaning of the mathematical symbols that you are using. The examiner will also want to know whether you understand the meaning and significance of the mathematical symbols that you write down. You are therefore required to take note of the meaning and content that the lecturer attaches to mathematical symbols and how the relationships between physical quantities in mathematical equations are read. You must become familiar with these and must be able to do likewise. Models and a description there of: As we are all aware, reality is extremely complicated. In class, we theorise with regard to the simplified reality. In theorising we make use of models in order to describe the simplified reality. Such a model can often be presented by means of a sketch using for instance arrows for forces and electric fields, a dot for a charge and an arrow to indicate the direction of movement of a charge. Distances, forces, magnetic fields, etc. are indicated by means of symbols in sketches of this nature. Often a sketch is essential to explain symbols and meanings and also to let derivations and discussions make sense. Take note of the large number of sketches / illustrations that you can find in your textbook and how frequently these are used in order to explain the learning material. It is therefore very important that you should understand the sketches and symbols used in your textbook. In tests and examinations you are also required to make meaningful use of sketches with symbols in them so that it will be clear to the examiner that you do indeed understand the work. Many questions cannot possibly be answered in a meaningful way without the use of appropriate sketches. In the laboratory, on the other hand, we create simple conditions so that only a few variables (or parameters) play a role and so that it is easy to control the variables. In that manner we are in a position to verify how different quantities change in respect of one another and what legitimate connection they have with regard to one another. Why study Physics? Each of the natural sciences studies the physical reality by looking at some or other aspect of it. Let us give a few examples: • Mathematics is a study of the number- and space-aspects of reality. • Physics covers the motion- and energy-aspects of nature. (As such Chemistry is actually a part of Physics). In Physics numbers, space, motion and energy play an vii important role. For this reason we cannot study Physics without a basic knowledge of Mathematics. To do Physics, we have to know Mathematics! • The biotic (life-) aspects of plants, animals or humans designate the biological, zoological and physiological fields of study. In these biological subjects numbers, space, motion, energy and the biotic aspects all come into play. To work in the biological subjects, one therefore needs a thorough knowledge of Mathematics, Physics and Chemistry. There is no aspect of our physical reality (objects, plants, animals, humans) that is not subjected to the laws of physics. • Gravity determines the direction of growth of plants; • The heartbeat is regulated by electrical pulses; • Engineers (whether mechanical, electrical, electronic or chemical) apply the laws of physics and chemistry in their everyday work. Therefore engineers study the applications of physics and chemistry. An engineer who does not understand the physics which is basic to these laws, will not be able to enjoy his work; • Physical measuring instruments and methods of measurements are being used in all natural sciences and cultural sciences (such as engineering, computer science and home economics); • The engineer, biologist, medical doctor, chemist or dietician cannot perform his or her tasks without using mass meters, pressure gauges, gauges of mechanical stress, voltmeters, X-ray machines, centrifuges, electron microscopes, gas chromatography systems, radiation detectors and computers (to name a few). The operation of all these instruments is based on physical principles and laws and to use them intelligently, one has to understand these principles and laws. In our modern lives we live and work in a physical -technological society. Just consider the modern car that abounds in modern technology. Consider the role that computers play in today’s life. Without an elementary knowledge of the basic laws and principles of nature that govern this technical environment, we may develop insecurity and become neurotic. The purpose of your study is not to make you one day performing a job like a robot. It is to enable you to become a balanced person who will lead an interesting and rewarding life in a satisfying career. This will only be possible if you could pursue your career as an intelligent, thinking person who does not feel threatened by modern technology, because you would understand your environment. Of course it is important that you should pass your exams, but it is even more important that you should understand and be in charge of yourself and your environment. Study practice: It is very important to develop the correct study methods. If you need help, consult me or someone else immediately. Should any problem occur during the semester, something that has a negative influence on your studies, do not hesitate to come and discuss it with me, your lecturer. Consult me timeously – do not wait until it is too late. Other forms of formal support are also available on the campus. The facilitator system is a programme that makes use of Subject Guardians and Student Facilitators, to assist first, second and sometimes third year students. It aims to empower them by developing a study strategy so that they can achieve the study outcomes in their viii modules. Cooperative study is promoted and it is hoped that a dynamic culture of study will develop on the campus. Students meet on a weekly basis in small groups. Group study sessions are being conducted by the facilitators. These facilitators are senior students that have been trained in guiding students towards correct study techniques. These facilitators have weekly consultations with the subject guardian (usually the first or second year lecturer in the subject) to identify the outcomes and decide which skills should be receiving more attention. During the group study sessions special attention is given to academic problems. The facilitators create a safe learning environment in which learners are encouraged to be active participants to the learning process. They are prompted to ask questions, pose problems and suggest answers to questions. In this way an insight into the subject matter is developed while communication skills, study strategies and other scientific abilities like critical thinking, analysis, organizing, etc. are being cultivated. The facilitator for NPHY111 will be introduced to you at the earliest opportunity. If you want to complete the module without experiencing any problems, it is essential that you should prepare thoroughly for every lesson. You are furthermore required to make yourself a set of core notes by availing yourself of the textbook (which is excellently written), the study guide, and the lecturer’s lectures. Also have a look at the Review and summary which is a good indication of what you are suppose to know as well as a summary of the key concepts of each Study. Furthermore you will be expected to be motivated and also to do self-study with the necessary self-discipline. The writing of definitions and laws: The most important laws in every study unit are indicated with an arrow () next to the most important concepts in each chapter. The writing of definitions is an art you have to master yourself. The lecturer is not going to rewrite each of the definitions from the textbook for you. Note that it has to be written concise, but still contain all relevant information, consisting of the following components: • Concise description of relevant aspects • A mathematical expression of the quantity defined (if relevant) • Declaration of all symbols • Scientific units of the quantity you are defining. • A sketch with captions (if relevant) Derivations (Proofs): The study guide provides you with a list of the derivations with which you need to be familiar and be able to reproduce in tests and in the examination. The number of marks that you earn will depend on the completeness of the derivation. Study the derivation and then make your own summary by taking the following into consideration: • What are the initial conditions? They should typically start with “Consider a system / particle / charge …” • Draw a sketch and explain. • With which law / equation(s) should you start? Next, apply it and explain the symbols. ix • Don’t merely write down equations; explain what you are doing and the reason for doing so. • Indicate how you progress from one step to the next. • The derivation is completed only when you have proved what you have been asked (final expression). • You will be awarded no marks at all if you just write down a number of formulas. Solving problems: Problem solving tactics are given in each chapter. Make use of it. Answer the Questions listed at the end of each chapter and the Checkpoints in every chapter. By answering the questions that appear at the end of each study unit and by solving the problems you will be exercising your understanding of and insight into the work that has been dealt with in that study unit. Try to find solutions for all the exercises and problems of each study unit independently in order to ensure that you understand the laws and principles and are able to apply them. Discuss the problems with the lecturer or with your fellow students. You will thus develop an insight of your own regarding the subject. The textbook provides complete information and advice in virtually every chapter with regard to the way you should handle problems. At the back of the textbook you are given the answers to all the checkpoints, to the odd number questions as well as the odd number exercises and problems that appear in each chapter. We will also spend time on the exercises in the tutorial lessons. Keep in mind that the tests and examinations will contain some problems (≈50%). Assessment Class tests, open book tutorials or e-learning tests During the semester, you will write a number of class tests as well as a test during the assessment week. The purpose of the class tests is to let you work diligently every day so that you may develop a full understanding of the knowledge presented to you and that you do not fall behind with the work. This will simultaneously contributes towards your participation mark, which is very important. The class tests will also contain a number of problems, laws, definitions and derivations. If there are multiple choice questions in the tests, it must be answered on a computer card by colouring in the circle that concurs with the correct answer. You will need a HB pencil for this purpose. If you don’t colour in the circles neatly, the card reader will ignore it and you will lose marks. After the class tests have been assessed it will be placed in the Physics mailboxes in the Physics building. It is your own responsibility to go and fetch it. The marks will be placed in a document on eFundi. You must check your marks. Besides the class tests you will also do a number of open book tutorials and any eLearning tests on eFundi will be announced in class. Assessment dates: _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ x Homework and assignments A very important aspect of any Physics course is the solving of problems. As soon as a chapter has been finished you should start working on the homework in the chapter. Some of the homework problems will be done in class or during the tutorial periods; the answers of the others will be put on eFundi. During the semester you will occasionally be asked to submit a few exercises as assignments. The assignments will be given in class and published on eFundi. The purpose of these homework and assignments is to help you to think about the Physics. It will do you no good to copy the work from someone else. The homework and assignments are important since they help you to understand the basic applications of physics, and you should therefore complete them meticulously, thus make sure that you regularly do this homework. The marks that you obtain with assignments also contribute towards your participation mark. The following rules apply when you submit assignments: • No late assignments will be accepted. • Each assignment is to be completed and submitted on A4-size lined pages and must be stapled in the top left-hand corner. You may not use pins or paper clips. Books, covers, etc. are not acceptable. • Use the same numbering for each problem as in the textbook or as on eFundi. • Draw a neat line across the page at the end of each answer to a problem. • Make certain that your surname and all your registered initials as well as your student number are clearly written on the cover of each completed assignment. • After the assignments have been assessed it will be placed in the mailboxes on the third floor on your way to the Physics practical laboratory. It is your own responsibility to go and fetch it. The marks will be placed on the board on the first floor in the Physics building; you must check your marks there. Dates for submission of assignments: ____________________________________ Absence • • • Students, who have been successful in the past, regard regular class attendance as one of the most important reasons for their success. If you have been unable to write a test owing to illness (or any other valid reason), you are required to submit at the first opportune moment to the Secretary at Enquiries in the Physics building, an original medical certificate (or any other original official document in verification of any other valid reason for your absence). Medical certificates and other supporting documentation must be submitted within ten days of the date of absence and it has to be the original document. The secretary will make a copy and hand the original back to you. N.B.: There will be no rewriting of tests that students have missed owing to their absence due to illness or any other reasons. Participation mark and final mark Requirements for examination admission: xi To gain entrance to the examination, you must obtain proof of participation. You will find the complete requirements for this in the yearbook of the Faculty of Natural and Agricultural Sciences. One requirement is a minimum participation mark of 40% (35% for bona fide first year students). Please note that the completion of practical work and satisfactory class attendance are required for proof of participation. The participation mark is made up of the final mark for the practical work and the final mark for theory. The mark for theory is made up of the marks obtained for the class tests, semester test, open book tutorials, class work (class attendance), eLearning tests on eFundi and the assignments. The final mark for the practical work and the final mark for theory are taken in a ratio of 1:3 when the participation mark is calculated. Requirements for a pass: A minimum module mark of 50%, provided that you have obtained 40% or more in the examination, is required for you to pass the module. The ratio of the examination mark in relation to the participation mark is 1:1. Examination All those students who have qualified for a participation mark in this module are entitled to two opportunities for writing the module examination. Both these module examinations consist of a single 3-hour paper. You may use either both of these opportunities or any one of your choice. Should you, however, opt to write both papers, the mark that you obtain at the second opportunity will be used to determine your module mark. No certificate is required if you do not write the first examination. Please note that it would be rather risky not to avail yourself of the opportunity to write the first examination. Should you, for instance, be unable to make use of the second opportunity for unforeseen reasons such as illness, there will not be a third (special) examination opportunity. Students who do not avail themselves of these two opportunities to write the examination or who have failed to pass the module after having written one or both of the examinations, will need to re-register for the module, pay the class fees again, and attend all classes in order to qualify for proof of participation anew and thus gain entrance to the next scheduled opportunity to write the examination. If there are multiple choice questions in the exam you will be handed a computer card on which you must answer these questions by colouring in the circle that concur with the correct answer. You will need a HB pencil for this purpose. If you don’t colour in the circles neatly, the card reader will ignore it and you will lose marks. Priorities In order to determine what is of importance, we make use of the following system: a specific priority and icon is allocated to each paragraph. We explain the meaning of this in the table below. Make sure that you understand the content of the table well, because it is the key to success in your studies. Priority Meaning Examination weight Number of lessons (hours) required by lecturer; number of hours of self-study by student a xii This is essential knowledge (which includes all laws, derivations and definitions); a comprehensive, in-depth knowledge of the work Approximately 30% is required. You are required not only to know and to understand the work, but must be able to apply it also as in the examples that have been worked out. b You need to go through this work (derivations, discussions and examples that have been worked out) and make absolutely certain that you understand it. It is essential that you should master the work. The definitions and basic principles of physics supported by mathematics are very important. Approximately 25% c Only a few central ideas are important in these sections. Make your own summary and interpretation as required in the study guide. This includes all exercises, questions and assignments. At most 30% d Self-study – mainly a repetition of schoolwork that is essential for mastering the work. We will deal with it but briefly or perhaps not at all in class. At most 10% e Supplementary study material, additional points of interest, and background information that is not of necessity of direct importance At most 5% Outcomes of the specific study unit or chapter Priority (a) determines the core study material. A student who has mastered priorities (a) and (b) can pass the module. In order to qualify for a distinction you need to do more than is required by priority (a) only. It is essential that you should know priority (d) very well since the omission of that will create a gap in your background knowledge. The assignments and homework afford you with an opportunity to prove that you have indeed mastered the work. Action words Test and examination questions always contain certain key or action words. It is essential for you to be familiar with the meanings of such action words and to know exactly what is required of you when you need to answer a question. With this in mind, a brief list of such verbs is given below: • Name In this instance, you need to write down the facts in a nutshell. • Describe You are required to perform at knowledge level. Characteristics, facts or results must be given in a logical, well-structured way. No comments or debating is required. • Define / State A mere reproduction of information / knowledge is required. It entails a clear, concise and authoritative description of a concept so that its meaning becomes clear. If you should make use of a mathematical equation in this instance, you need to explain all the symbols that you use in the equation, explain the meaning of each symbol, and also supply the SI unit of each. xiii • Give a mathematical expression for: You are required to explain all symbols used in the expression: you need to state what each symbol represents and give its SI unit. • Give an overview A large volume of knowledge must be summarised and reproduced logically and systematically while retaining the essence of the matter. • Explain A matter is stated simply in order that the reader may understand it fully. You must make use of examples, illustrations and descriptions, while also providing reasons for statements and results. • Prove Bear out the facts by producing proof in support of them. Look again at the heading “WORKING METHOD IN PHYSICS AND HOW TO STUDY”, for how to tackle a “derivation” or prove a “statement”. • Compare / Distinguish between You should approach this with care. Do not first discuss one matter and then the next one. Facts, events or problems are contrasted and similarities or differences are highlighted. Hint: answer this type of question in tabular format Before we start – a bit of inspiration: We as lecturers are very enthusiastic about our field, Physics. The world of physics is so wide and each individual lecturer has become an expert on his or her field of research. Lecturers will most definitely share their experience of their specific research fields with their students when teaching physics since the lecture’s mandate is not only to teach technical physics with real-life examples, but also to inspire the scientists (you) of the future. Absorb as much as possible from your lecturers and use this module to lay the foundation to be the best scientist you can be. Icons xiv Time allocation Learning outcomes Study material Assessment / Assignments Individual exercise Group Activity Example Reflection Warning against plagiarism ASSIGNMENTS ARE INDIVIDUAL TASKS AND NOT GROUP ACTIVITIES. (UNLESS EXPLICITLY INDICATED AS GROUP ACTIVITIES) Copying of text from other learners or from other sources (for instance the study guide, prescribed material or directly from the internet) is not allowed – only brief quotations are allowed and then only if indicated as such. You should reformulate existing text and use your own words to explain what you have read. It is not acceptable to retype existing text and just acknowledge the source in a footnote – you should be able to relate the idea or concept, without repeating the original author to the letter. The aim of the assignments is not the reproduction of existing material, but to ascertain whether you have the ability to integrate existing texts, add your own interpretation and/or critique of the texts and offer a creative solution to existing problems. Be warned: students who submit copied text will obtain a mark of zero for the assignment and disciplinary steps may be taken by the Faculty and/or University. It is also unacceptable to do somebody else’s work, to lend your work to them or to make your work available to them to copy – be careful and do not make your work available to anyone! Plagiarism is a serious offence and you should familiarise yourself with the plagiarism policy of the NWU. http://library.nwu.ac.za/copyright-and-plagiarism Please refer to the Policy on Academic Integrity which is found on the following website: http://www.nwu.ac.za/content/policy_rules xv Study unit 1 Study division A: Kinematics and vectors Study unit 1 MEASUREMENT Study material This self-study Study Unit consists of Chapter 1 in the textbook. You will not be examined about this, but it is important that you study this attentively. Study the following attentively The most important concepts in this chapter are: The SI-system Base units Standard kilogram Derived units Standard meter Changing units Study outcomes After completion of this Study Unit you should be able to: • • • • know certain concepts you need to complete this module successfully. know and understand the SI-system. convert units, e.g. from km/h to m/s. know how we deal results with colleague scientists. Study time Contact sessions: 0 periods Self-study: 2 hours 1 Study Unit 1 Important information D What is Physics? Read through. D Measuring things: Read through. D The International System of Units: Make sure you know the base units and the derived units. You must know Table 1.2. D Changing units: The rule explained here and the examples are very important. Take note of the “problem solving tactics” – it helps to simplify your work. D Length: Read through and take note of Table 1.3. The example is not important. D Time: Read through. D Mass: Read through. Take note of Table 1.5. Make sure that you know what is meant by atomic mass units (u). Reflection Review and Summary Why do we measure things? How do we deal results with colleague scientists? What is the SI system? How are units changed? See the “Review and summary” which is a good summary of what you should know. The core facts of this Study Unit is summarised here. 2 Study unit 2 Study unit 2 MOTION ALONG A STRAIGHT LINE Study material This Study Unit consists of Chapter 2 in the textbook and is the key Chapter to describe any kind of motion. This is also revision of school work. It is important to that you master this work. Study the following attentively The most important concepts in this chapter are: Kinematics Instantaneous speed Position Average acceleration Distance Instantaneous acceleration Displacement Constant acceleration Average velocity Equations of motion Instantaneous velocity Free fall Average speed Terminal speed Study outcomes After completion of this Study Unit you should be able to: • • • define and discuss the above-mentioned concepts and be able to derive and apply them where applicable. describe motion along a straight line. derive and apply the equations of motions. Study time Contact sessions: 2 hours Self-study: 4 hours 3 Study Unit 2 Important information D What is Physics? Read through. C Motion: Make sure that you know and understand the three assumptions that are made in this Chapter. A Position and Displacement: Always give the definition of displacement (equation 2.1) in terms of a point of reference. Displacement has both magnitude and direction and is thus a vector quantity. Difference between displacement and distance. “Checkpoint 1”: Do them all to check whether you understand what is done. A Average velocity and speed: Know both definitions (Equations 2.2 and 2.3). What are the units? Figures 2.2, 2.3 and 2.4 are essential to understand the basic concepts – NB “x vs t” graphs are not pictures of the path of the motion on the ground. Thoroughly work through the Sample Problem – which will guide you in the correct approach while doing problems. A Instantaneous velocity and speed: Know the definition (Equation 2.4) and the unit. Make sure that you understand it is the tangent to x vs t graph. Understand the remark about speed at the bottom of the page. The Sample Problem and Checkpoint 2 are important. A Acceleration: Know the definitions (Equations 2.7, 2.8 and 2.9) as well as the SI unit. Take note of g as a unit for acceleration. Work through the Sample Problem and Checkpoint 3. A Constant acceleration: A Special case Derivation 1: You must be able to derive the Equations of motion (Equations 2.11, 2.15 and 2.16) for constant acceleration. Checkpoint 4 is important. Another look at Constant acceleration II: 4 Study unit 2 You can omit this. B Free-fall acceleration: Free fall – what is meant by this? Do the Sample Problem and Checkpoint 5. C Graphical Integration in Motion Analysis: What does the area below a graph represent? Reflection Review and Summary This is a good summary of the core facts of this Study Unit. Individual activity Homework: 2, 28, 37, 43, 62 5 Study Unit 3 Study unit 3 VECTORS Study material This Study Unit consists of Chapter 3 in the textbook and contains the core information for the extension from one to more dimensions. You will need this Chapter a few times during this year, so it will be great if you understand it from now on. Important information ur To represent a vector, the textbook uses an arrow above the symbol, e.g. a . In hand writing we underline the symbol, e.g. a. Other textbooks use bold letters, e.g. a. Study the following attentively The most important concepts in this chapter are: Scalar Vector components Vector Unit vectors Displacement vector Component Addition Addition of vectors Scalar product Resultant Vector product Study outcomes After completion of this Study Unit you should be able to: • • • define and discuss the above-mentioned concepts and be able to derive and apply them where applicable. know when a physical quantity is a vector or a scalar. know and apply the rules for vector calculations. Study time Contact sessions: 2 hours Self-study: 4 hours 6 Study Unit 3 Important information D What is Physics? Read through. A Vectors and Scalars: Scalars are quantities with magnitude only. Vectors have magnitude and direction and are represented by an arrow. (e.g. displacement) D Adding vectors geometrically: This is revision of known work. Addition and subtraction. Commutative and associative laws Make sure that you understand all the figures. Do the first Sample Problem and Checkpoint 1. B Components of vectors: The components of a vector are scalars and thus easy to work with. The components can be written as component vectors by using unit vectors (see the next paragraph). Equations 3.5 and 3.6 give the method to find the components and also to combine them again. Checkpoint 2 and the Sample Problem are important. The Problem-Solving Tactics do significant revision of the angular units and trigonometry functions. B Unit vectors: A formal way to write a vector in terms of its components. B Adding vectors by components: Make sure that you understand equations 3. 9 – 3.12 and the Sample Problem. E Vectors and the laws of Physics: Read through. A `Multiplying Vectors: Al three ways in which vectors can be multiplied are important. (i) Multiplying a vector by a scalar: Increase a vector a with a quantity s. The direction is the direction of a if s is positive but the opposite direction if s is negative. 7 Study Unit 3 (ii) Scalar Product or dot product: Multiplying a vector by a vector and the result is a scalar. The method is given in equation 3.20. Make sure that you understand figure 3.18. Equation 3.23 gives it in terms of components. Do Checkpoint 4 and the Sample Problem. (iii) Vector- or cross product: This produces a third vector that is perpendicular on the other two vectors. The method is given in equation 3.27. Make sure that you understand the right-hand rule in figure 3.19. Do Checkpoint 5 and the Sample Problems. Reflection Review and Summary Individual activity Homework: 15, 18, 38 8 Study Unit 4 Study unit 4 MOTION IN TWO AND THREE DIMENSIONS Study material This Study Unit consists of Chapter 4 in the textbook. By writing the definitions of motion in terms of vectors we can describe the two- and three dimensional motions in terms of motion in a straight line and can thus apply the results of Study Unit 2. Study the following attentively The most important concepts in this chapter are: Position and displacement Uniform circular motion Velocity Centripetal acceleration acceleration Relative motion Projectile motion Study outcomes After completion of this Study Unit you should be able to: • • • • • define and discuss the above-mentioned concepts and be able to derive and apply them where applicable. know that all the cases done in this study unit can be described in terms of motion in a straight line and that we can thus apply the results of Study Unit 2. do projectile motion with confidence. understand circular motion, because you will need it again. understand relative motion. Study time Contact sessions: 2 hours Self-study: 4 hours 9 Study Unit 4 Important information D What is Physics? Chapters 2 and 3 are combined – read through. B Position and displacement: Both are vectors. Make sure you know equations 4.1, 4.2 and 4.3. Do the Sample Problem. B Velocity: Another vector quantity. The definitions are given in equations 4.8 and 4.10. Make sure that you know the component notation in equation 4.11 and the implication there of in equation in 4.12. Instantaneous velocity is the tangent to the path of the particle. Checkpoint 1 and the Sample Problem are important. B Acceleration: Also a vector quantity with its definitions in equations 4.15 – 4.18. Do the Sample Problem as well as Checkpoint 2. A Projectile motion: Projectile motion is the motion of a particle that is launched with an initial velocity v and with its vertical acceleration the free-fall acceleration (air friction is negligible). NB: The horizontal and vertical motions are independent of each other and have different equations of motion – see figure fig 4.9. See figures 4.10, 4.11 and 4.12 together with its discussions to convince you about it. Only the parts on horizontal and vertical motion are of importance. Omit the equation for the path, the horizontal range and the effects of the air. Do Checkpoint 4 and the first Sample Problem. A Uniform circular motion: Circular motion with constant speed. The particle accelerates because the direction of its velocity changes continuously. Derivation 2: The calculation of the magnitude and direction of the acceleration – also called the centripetal acceleration (make sure about the unit vectors). Do Checkpoint 5 and the sample Problem. B Relative motion in one dimension: 10 Study Unit 4 Make sure that you understand and know figure 4.18 and equation 4.41. The conclusion that follows equation 4.42 is very important. Do the Sample Problem. B Relative motion in two dimensions: Expansion of the previous paragraph – read through. Reflection Review and Summary Individual activity Homework: 14, 30, 61, 70 11 Study Unit 5 Study division B: Dynamics Study unit 5 FORCE AND MOTION I Study material This Study Unit consists of Chapter 5 in the textbook. Now that we know how to describe motion, we ask ourselves about the cause of motion. Study the following attentively The most important concepts in this chapter are: Force Inertial mass Newton’s first law Newton’s second law Inertial frames Newton’s third law Study outcomes After completion of this Study Unit you should be able to: • • • define and discuss the above-mentioned concepts and be able to derive and apply them where applicable. know what is meant by a force and its action. know and apply Newton’s laws. Study time Contact sessions: 2 hours Self-study: 4 hours Important information D What is Physics? Read through. 12 Study unit 5 D Newtonian Mechanics: Read through. B Newton’s first law: Memorise the law and take note that friction is negligible in this Chapter. B Force: A force is measured by the acceleration caused by it. It is thus also a vector quantity and the unit is the newton (N). Note that all vector calculations also hold for forces and that we always look at the resultant force on a body. Note that all the vector calculations are also true for forces and that we always work with the resultant force on a body. Thus Newton’s first law may be re formulated. What is an inertial frame? This is important in mechanics. See that you understand the discussion of figure 5.2. Do Checkpoint 1 as revision of vectors. D Mass: Mass is an intrinsic property of matter. Work through this. b Newton’s second law: Memorise the law in words as well as the mathematical expression (equation 5.1). You must understand the fact that this law is also true for the components of forces and that the component equations are independent. Do the two Sample Problems and Checkpoint 2. B Some particular forces: (1) Gravitational force: The force of attraction of the earth on a body with mass m. (2) Weight: The magnitude of the gravitational force on a body. – How do we measure weight? – It is not the mass of the body. (3) Normal force: When an object rests on a surface, the normal force equals the magnitude of the weight and acts in opposite direction. Checkpoint 3 is important. (4) Friction: Is a force that opposes motion. (5) Tension: Study figure 5.9 and its description where the tension is the magnitude of the force on the body. Checkpoint 4 is important. B Newton’s third law: 13 Study Unit 5 Work through. Make sure that you understand the law and that you know it in words and mathematically. Figures 5.10 and 5.11 as well as Checkpoint 5 are important. B Applying Newton’s laws: The first Sample Problem will be done in class. Work through the other Sample Problems Reflection Review and Summary Individual activity Homework: 14, 38, 64 14 Study unit 6 Study unit 6 FORCE AND MOTION II Study material This Study Unit consists of Chapter 6 in the textbook. Study the following attentively The most important concepts in this chapter are: Static friction Drag force and terminal speed Kinetic friction Uniform circular motion Coefficient of static friction Centripetal acceleration Coefficient of kinetic friction Study outcomes After completion of this Study Unit you should be able to: • define and discuss the above-mentioned concepts and be able to apply them in simple calculations. • realise that we come closer to reality by the discussion of friction. • know how to determine friction and understand its connection with the normal force and the weight of a body. Study time Contact sessions: 2 hours Self-study: 4 hours 15 Study Unit 6 Important information D What is Physics? Read through. B Friction: Figure 6.1 and its discussion are important to understand friction (static and kinetic) and how it influences motion. Work through the part that describes the microscopic cause of friction. C Properties of friction: You must know the properties of friction and equations 6.1 and 6.2 as well as the connection between the coefficient of static and kinetic friction. Do Checkpoint 1 as well as the two Sample Problems D Drag force and terminal speed: Read through. You must know the meaning of drag force and terminal speed. Omit the Sample Problem E Uniform circular motion: See Chapter 4 and consider the different types of circular motion. Read through and omit the Sample Problems. Do Checkpoint 2. Reflection Review and Summary Individual activity Homework: 20, 23, 28 16 Study unit 7 Study unit 7 KINETIC ENERGY AND WORK Study material This Study Unit consists of Chapter 7 in the textbook. It is sometimes difficult to describe motion in terms of vector quantities. We therefore develop a scalar theory in this chapter and the following chapters to simplify those cases. Study the following attentively The most important concepts in this chapter are: Kinetic energy Work done by a variable force Work Work done by a spring force Work-kinetic energy theorem Power Work done by Gravity Study outcomes After completion of this Study Unit you should be able to • • • • define and discuss the above-mentioned concepts and be able to derive and apply them where applicable. ensure yourself that you thoroughly understand the alternative description of motion. master the core concepts Work and Kinetic energy. know and apply the Work-kinetic energy theorem. :Study time Contact sessions: 2 hours Self-study: 4 hours Important information D What is Physics? Read through. 17 Study Unit 7 D What is Energy? Read through. A Kinetic Energy: This is a new concept with lots of meanings. It is a scalar quantity that simplifies the study of motion. In this chapter we will concentrate on kinetic energy (K), which depends on the state of motion of a system (see the definition in equation7.1). The unit is the joule (J) – see equation 7.2. Read the Sample Problem. A Work: If the state of motion of a system changes, it accelerates and according to Chapter 5 a force then acts on it. We say then that work was done on the system by the force that caused the change in the state of the motion. Work and energy are thus closely related. A Work and kinetic energy: (1) An expression for work: Derivation 3: Derive equation 7.8 from equation 7.3. Thus work depends on the displacement of a system and the force component in the direction of the displacement. When is the work done positive and when negative? What is the unit of work (see equation 7.8)? (2) The work-kinetic energy theorem: Equation 7.10 and 7.11 are very important, but is just another notation for equation 7.5. Do Checkpoint 1 as well as the two Sample Problems. B Work done by a Gravitational force: Only equation 7.12 is important. Work through the rest of the paragraph. This will give you the necessary exercise in the work of §7.5. Do the first Sample Problem. B Work done by a spring force: You must understand figure 7.10 (7.9 in the 9th edition) to understand Hooke’s law (equation 7.21). This force is thus a variable force (non uniform). Derivation 4: Work done by the spring force (equation 7.25) 18 Study unit 7 Do the Sample Problem as well as Checkpoint 2. A Work done by a variable force Make sure that you understand the General concepts of integration on this page very clearly – especially the transformation of equation 7.29 to equation 7.32. You will find the integrals on page A11. Omit the rest of this paragraph. b Power: This is an important quantity that is used very often to describe energy consumption. This is thus the rate at which work is done. There are different units for power, but we use the watt (W). Make sure that you remember equations 7.43 and 7.48 to use later on. Reflection Review and Summary Individual activity Homework: 3, 15, 37, 41, 46 19 Study Unit 8 Study unit 8 POTENTIAL ENERGY AND CONSERVATION OF ENERGY Study material This Study Unit consists of Chapter 8 in the textbook. Study the following attentively The most important concepts in this chapter are: Potential energy Elastic potential energy conservative force Conservation of mechanical energy Work-potential energy theorem Work done by an external force Gravitational potential energy Dissipative force Path independence of conservative forces Law of conservation of energy Study outcomes After completion of this Study Unit you should be able to: • • define and discuss the above-mentioned concepts and be able to derive and apply them where applicable. know and apply the work-energy theorems and laws of conservation. Study time Contact sessions: 2 hours Self-study: 4 hours Important information D What is Physics? 20 Study unit 8 Read through. B Work and Potential energy: Most bodies have the potential to do work. There are multiple reasons for this. The concept “potential energy” (U) together with kinetic energy forms a powerful whole to describe the motion of bodies. The example in figure 8.2 and its discussion are important. Take note of equation 8.1. Make sure that you know what a conservative force is – it simplifies lots of problems. C Path independence of conservative forces: When is a force a conservative force? The two arrows and figure 8.4 are important. Omit the proof. Do Checkpoint 1 Do the Sample Problem. B Determining potential energy values: Derivation 5: Expressions for Gravitational potential energy and elastic potential energy. A body has gravitational potential energy because of its position that means because it is on a distance away from the earth. A spring has elastic potential energy because of its deformation, in other words because it is stretched or compressed. Do the Sample Problem and Checkpoint 2. B Conservation of mechanical energy: The definition of mechanical- or total energy (equation 8.12) is very important. Derivation 6: Conservation of mechanical energy (equation 8.17). The part from equation 8.17 to the bottom of the page, as well as figure 8.7 with its description is very important. Do Checkpoint 3 and the Sample Problem. C Reading a potential energy curve: Equation 8.22 will be used very often. You must be able to interpret the potential energy curve in figure 8.9. Read the part about turning points and equilibrium points – this will help you with the problem solving. Do Checkpoint 4. B Work done on a system by an external force: Read thoroughly about the connection between work and energy. The work-energy concept (equation 8.26) is very important. 21 Study Unit 8 Note the part about friction, but omit Checkpoint 5. It is important to note that when conservative and non-conservative forces (e.g. friction) act on an object and thus do work, then the work-kinetic energy theorem (in Chapter 7) can still be used. The conservation of mechanical energy does not hold here anymore. Do the Sample problem. D Conservation of energy: Read thoroughly – this gives us a good insight in the discussed conservation laws. Do the Sample Problem. Again have a look at the previous paragraph about what to do if friction is involved. Reflection Review and Summary Individual activity Homework: 2, 27, 33, 54, 60 22 Study unit 9 Study unit 9 CENTRE OF MASS AND LINEAR MOMENTUM Study material This Study Unit consists of Chapter 9 in the textbook. Study the following attentively The most important concepts in this chapter are: Centre of mass Linear momentum Linear momentum for a system of particles Newton’s second law in terms of momentum Law of conservation momentum Collisions Elastic collisions Impulse Inelastic collisions The Impulse-momentum theorem Collisions in two dimensions of Linear Law of conservation of momentum during collisions Study outcomes After completion of this Study Unit you should be able to: • • • • • define and discuss the above-mentioned concepts and be able to apply them where applicable. know how to handle systems of particles. master the important concept of momentum as well as the law of conservation that goes with it. know what collisions are and how we handle it together with the conservation laws. know that the concept impulse and its connection with momentum are important to describe collisions. 23 Study Unit 9 Study time Contact sessions: 2 hours Self-study: 4 hours Important information D What is Physics? Read through and make sure that you understand figure 9.1. C Centre of mass: Systems of particles – make sure you understand this concept. Omit the part on solid bodies as well as Checkpoint 1 and the two Sample Problems. D Newton’s second law for a system of particles: Work through – it is identical to that of a single particle. A Linear momentum I: This is a very important concept – make sure that you know the definition (equation 9.22). Newton’s second law in terms of momentum will be used very often. Ensure that you understand Checkpoint 3. D Linear momentum of a system of particles: Equation 9.25 and the definition in words are important. A Collision and Impulse: You have to master this new concept “impulse”. (To do so, you must understand figure 9.9). It is important to remember the connection between momentum and impulse (equation 9.31) – also that it is actually three independent equations. The Sample Problem is for self-study. Omit ‘Series of collisions’. Do Checkpoints 4 and 5. A Conservation of linear momentum: An important and usable theorem. Make sure that you know the conservation of momentum (equation 9.42) in words. Do Checkpoint 6 and the Sample Problems. B Momentum and kinetic energy in collisions: 24 Study unit 9 Important approaches in the handling of collisions. Make quite sure that you can distinguish between elastic and inelastic collisions. Also make certain that you know the conservations during the different type of collisions. C Inelastic collisions in one dimension: Make use of the approach definition to write down equation 9.50. The equation may be simplified for stuck-together bodies. The motion of the centre of mass; figure 9.16 is important. Do the Sample Problem. C Elastic collisions in one dimension: What is the approach for elastic collisions? Derivation 7: Derive equations 9.67 and 9.68. You must know the three special situations. ‘Moving Target’: read through. Do the Sample Problem and Checkpoint 8. E Collisions in two dimensions: This is an extension of the previous paragraphs. Read through. An example will be done in class. C Rockets: Another example will be done in class. Reflection Review and Summary Individual activity Homework: 22, 24, 35, 49, 51 25 Study Unit 10 Study unit 10 ROTATION Study material This Study Unit consists of Chapter 10 in the textbook. Study the following attentively The most important concepts in this chapter are: Translation and rotation Constant angular acceleration Angular position Relation between linear and angular variables Angular displacement Average angular velocity Kinetic energy of rotation Instantaneous angular velocity Moment of inertia Average angular acceleration Torque Instantaneous angular acceleration Study outcomes After completion of this Study Unit you should be able to: • • define and discuss the above-mentioned concepts and be able to apply them where applicable. know which variables to use in the description of rotation and what their equivalents in rectilinear motion are. Study time Contact sessions: 2 hours Self-study: 4 hours 26 Study Unit 10 Important information D What is Physics? Read through. A Rotation variables: We consider the rotation of a rigid body about a fixed axis... - Angular position (equation 10.1) measured in radians (equations 10.2 and 10.3). (Also see figure 10.3). - Angular displacement (equation 10.4) also in radians. The sign rule is important. - Angular velocity (equation 10.6) in rad/s. It is the same for the whole body although the speed is different. - Angular acceleration (equation 10.8) and its unit. Do the first Sample Problem and Checkpoint 1. D Are angular quantities vectors? Very strange properties. D Rotation with constant angular acceleration: Take note of Table 10.1. It shows that the equations of motion for pure rotation are similar to those for linear motion in a straight line. Do Checkpoint 2. Do the two Sample Problems. B Relating the linear and angular variables: Derivation 8. Important paragraph that connect the linear variables to the angular variables. Make certain that you know, understand and are able to derive (prove) and use equations 10.17, 10.18, 10.22 and 10.23. Do Checkpoint 3. b Kinetic energy of rotation: Understand the concept of rotational inertia (equation 10.33) – it replaces mass in rotational motion. Derivation 9: The kinetic energy of a rotating body. Do Checkpoint 4. D Calculating the rotational inertia: 27 Study Unit 10 A Torque: read together with §11.4 (§11.6 in 9th edition) Torque plays the role of force in rotational motion. This is the first time that we use the vector product to define a quantity (equations 10.39 and 11.14). Line of action and momentum are handy concepts which are also used in the practicals. The unit is newton-metre (which is also the unit for work done – do not confuse the two). Do Checkpoint 6. E Newton’s second law for rotation: Equation 10.42 is the rotation equivalent. E Work and rotation kinetic energy: Read through. Reflection Review and Summary Individual activity Homework: 4, 10, 23 28 Study Unit 11 Study unit 11 ROLLING, TORQUE ANDANGULAR MOMENTUM Study material This Study Unit consists of Chapter 11 in the textbook. Study the following attentively The most important concepts in this chapter are: Rolling Angular momentum Newton’s second law in angular form Law of conservation of angular momentum Study outcomes After completion of this Study Unit you should be able to: • • define and discuss the above-mentioned concepts and be able to apply them where applicable. be familiar with these rotation equivalents of the linear variables. Study time Contact sessions: 1 hour Self-study: 2 hours 29 Study Unit 11 Important information D What is Physics? Read through. D Rolling: Rolling is a combination of rotation and translational motion. D The kinetic energy of rolling: Read through. E The forces of rolling: Omit E The yo-yo: Omit, but very interesting to read through. A Torque: Read with §10.6 (§10.8 in 9th edition). Equation 11.14 and figure 11.10 are important. Do the Sample Problem and Checkpoint 3. A Angular momentum: Another important quantity for rotation; it is equivalent to momentum in linear motion. It is defined by equation 11.18 and figure 11.12. Make sure that you also know the unit. The meaning of the direction of the angular momentum is important. Do Checkpoint 4 and the Sample Problem. D Newton’s second law in angular form: The vector sum of all the torques on a particle equals the rate of change of the angular momentum of the particle. D The angular momentum of a system of particles: The angular momentum L of a system of particles is the vector sum of the angular momentum of the individual particles. C The angular momentum of a rigid body: 30 Study Unit 11 The component of the angular momentum parallel to the rotation-axis of a rigid body that rotates about a fixed axis is given by L = Iω . Table 11.1 is handy to use. Do Checkpoint 6 A Conservation of angular momentum: This is again the rotational equivalent of the linear motion. The examples with the figures from 11.16 to 11.20 are very interesting and incredible implications of the law of conservation. D Precession of a Gyroscope: Read through. Reflection Review and Summary Individual activity Homework: 21, 46 31 Study Unit 12 Study division C: Statics Study unit 12 EQUILIBRIUM Study material This Study Unit consists of Chapter 12 in the textbook. Study the following attentively The most important concepts in this chapter are: Static-and dynamic equilibrium Requirements of equilibrium Stable-, unstableequilibrium Centre of gravity and neutral Study outcomes After completion of this Study Unit you should be able to: • • define and discuss the above-mentioned concepts and be able to apply them where applicable. know the requirements of equilibrium and be able to apply it. Study time Contact sessions: 3 hours Self-study: 6 hours Important information D What is Physics? Read through. D Equilibrium: 32 Study Unit 12 Read through attentively – this is a summary of what is done already. A Requirements of equilibrium: You must know the whole paragraph and be able to apply it. Do Checkpoint 1. D Centre of gravity: This will be done completely in the practicals. Take note that it is in most cases the body’s centre of gravity is coincident with the body’s centre of mass. Omit the derivation and Checkpoint 2. A Examples of static equilibrium: Do the Sample Problems. Some will be done in class. E Indeterminate structures: Read through. C Elasticity: Reflection Review and Summary Individual activity Homework: 3, 4, 12 (10th edition) 10, 28, 12 (9th edition) 33 Study Unit 13 Study unit 13 GRAVITATION Study material This Study Unit consists of Chapter 13 in the textbook. Study the following attentively The most important concepts in this chapter are: Force of gravity Newton’s law of Gravitation Study outcomes After completion of this Study Unit you should be able to • • define and discuss the above-mentioned concept and law and be able to apply them where applicable. know the law of Gravitation and be able to apply it. Study time Contact sessions: 1 hour Self-study: 2 hours Important information D What is Physics? Read through. A Newton’s law of Gravitation: You must know the law and be able to apply it. D Gravitation and the principle of superposition: Read through. 34 Study Unit 13 D Gravitation near the Earth’s surface: Important to take note of. D Gravitation inside the Earth: Same as previous paragraph. E Gravitational potential energy: Already done. E Kepler’s laws: For those who are interested – the principles that controls the motion of planets. E Satellites: Read through. E Einstein and gravitation: Read through this – especially if you are going to study Physics further. Reflection Review and Summary Individual activity Homework: 18 (10th edition) 11 (9th edition) 35 Study Unit 14 Study division D: Hydrostatics and hydrodynamics Study unit 14 FLUIDS Study material This Study Unit consists of Chapter 14 in the textbook. Study the following attentively The most important concepts in this chapter are: Fluid Pascal’s principle Density Archimedes’ principle Pressure, absolute pressure, gauge pressure Equation of continuity Manometer Bernoulli’s equation Study outcomes After completion of this Study Unit you should be able to: • • Define and discuss the above-mentioned concept and law and be able to apply them in simple calculations. Analyze fluids in motion by derive and apply the Equation of continuity derive and apply Bernoulli’s equation Study time Contact sessions: 4 hours Self-study: 8 hours 36 Study Unit 14 Important information D What is Physics? Read through. A What is a fluid? Read through. You must know what a fluid is. A Density and pressure: Know the definitions for density and pressure. Work through the Sample Problem. A Fluids at rest: The pressure at a point in a fluid in static equilibrium depends on the depth of that point but not on any horizontal dimension of the fluid or its container. Derivation 10: Determine an equation for the pressure at a point in a fluid as a function of depth. Do Checkpoint 1 and the two Sample Problems. A Measuring Pressure: Know the operation of a mercury barometer and an open-tube manometer. A Pascal’s principle: Derivation 11 You most know Pascal’s principle and its derivation. Also see the application of the hydraulic lever. Can you think about some other applications? A Archimedes’ principle: Make sure that you know and understand Archimedes’ principle and that you are able to apply it. Do Checkpoint 2 and the Sample Problem. A Ideal fluids in motion: Know the properties of an ideal fluid. A The Equation of continuity: Derivation 12 The Equation of continuity is an important concept; you must know its derivation and applications. It is also an example of a conservation law. Do Checkpoint 3 and the Sample Problem. 37 Study Unit 14 A Bernoulli’s equation: Derivation 13 You must know Bernoulli’s equation and be able to derive and apply it. The Equation of continuity is about the conservation of matter in a liquid, but Bernoulli’s equation is about the conservation of energy in liquids. Do Checkpoint 4 and the two Sample Problems. Reflection Review and summary Individual activity Homework: 11, 15, 37, 53, 67 (10th edition) 10, 2, 58, 53, 33 (9th edition) 38 Study Unit 15 Study division E: Periodic motion and waves Study unit 15 OSCILLATIONS Study material This Study Unit consists of Chapter 15 in the textbook. Study the following attentively The most important concepts in this chapter are: Free oscillations Phase angle SHM Angular frequency Frequency Pendulum Period Damping Amplitude Forced oscillations Phase Resonance Study outcomes After completion of this Study Unit you should be able to: • • • • define, discuss and derive this kind of motion and the above-mentioned concepts and be able to apply it in simple calculations. know where oscillations occur in nature explain oscillations mathematically solve simple problems on oscillations Study time Contact sessions: 2 hours Self-study: 4 hours 39 Study Unit 15 Important information D What is Physics? Read through. Here you get a brief scope about the occurrence of oscillations in everyday life. This kind of motion forms the base of a variety of phenomena. A Simple harmonic Motion As in lots of other cases in Physics, we use the simplest case to describe a natural phenomenon mathematically. Simple harmonic Motion (SHM) is the simplest case in the study of oscillations. The following important definitions concerning SHM are given in this section: Frequency Period Amplitude Phase Phase angle Angular frequency Make sure that you understand these definitions. The mathematical expression for a SHM is very important. It is given by equation15-3: x(t) = xm cos (ωt + φ) and the symbols are explained in Figure 15-3 (15-2 in 9th edition). Figure 15-5 (15-3 in 9th edition) is a plot of x versus t. Do Checkpoint 1. B The Force law: Derivation 14 Work through. Note the negative sign in equation 15-10 which indicates that the direction of the restoring force is opposite to the direction of the displacement. Work through the two Sample Problems, Checkpoint 2 (this one is not in the 9th edition) and Checkpoint 3 (Checkpoint 2 in 9th edition). c Energy in SHM: Derivation 15 Like with all mechanical motion, the total energy is the sum of the potential energy and the kinetic energy. See whether you can prove that the energy of a SHM is constant and depends only on k and (amplitude)2. Refer back to Chapter 8 in order to understand the origin of the relation for potential energy. Do Checkpoint 4 (Checkpoint 3 in 9th edition) and the Sample Problem. E Angular SHM: Read Through. C Pendulums: (Period of a pendulum) We will only study the simple harmonic pendulum. 40 Study Unit 15 C 15.7 SHM and Uniform Circular motion: SHM is the projection of uniform circular motion on a diameter of the circle in which the circular motion occurs. Example: Jupiter’s moons. E Damped SHM: Motion is always damped by forces. This is thus closer to the truth than the models we studied. Read through. D Forced oscillations and Resonance: This is one of the most general phenomena in nature and in industry. Make sure that you know what resonance is. Make a list of resonance phenomena. Reflection Review and Summary Study time Homework: 5, 13, 20, 42 (10th edition) 13, 33, 30, 2 (9th edition) 41 Study Unit 16 Study unit 16 WAVES Study material This Study Unit consists of Chapter 16 in the textbook. Study the following attentively The most important concepts in this chapter are: Waves Wave number Transverse waves Period Longitudinal waves Speed of a travelling wave Wave length Energy and Power Frequency and angular frequency Principle of Superposition Amplitude Standing waves Phase Resonance Study outcomes After completion of this Study Unit you should be able to: • • • • • • • 42 define, discuss and derive the above-mentioned concepts and be able to apply it in simple calculations. know what waves are and how to handle it. know the difference and similarities between oscillations and waves. know where waves occur in nature. distinguish between longitudinal and transverse waves. describe waves mathematically solve simple problems about waves. Study Unit 16 Study time Contact sessions: 2 hours Self-study: 4 hours Important information D What is Physics? Read through D Types of waves: Tale note of examples of mechanical waves, electromagnetic waves and matter waves. B Transverse and longitudinal waves: Make sure that you are able to define the two types (longitudinal and transverse) and that you know examples of each. Water waves are transverse waves and sound waves are longitudinal. A Wavelength and frequency: The basic description of waves is given here. Know the difference between a wave and an oscillation. Their mathematical explanation is very similar. In the case of an oscillator it is only necessary to describe the displacement in terms of the rest position. The latter is also true for a wave, but also how this displacement propagates through space, for example in the x–direction. Make sure that you know the meaning of each of the following concepts:- amplitude, phase, wavelength, wave number, period, frequency and angular frequency. The wave equation 16.2 and figures 16.3 and 16.4 are important. - Amplitude and phase are as for oscillations - Wavelength and wave number typify the spatial aspect of the wave. - Period, frequency and angular frequency typify the time aspect of the wave. Do Checkpoint1. A The speed of a travelling wave: Derivation 16: derive equation 16.13. Make sure how to determine the direction of motion of a wave. Do Checkpoint 2. E Wave speed on a stretched string: Read through. 43 Study Unit 16 e Energy and power: Read through. E The wave equation: A Principle of Superposition: A simple but cogent principle that is used very often and formulated as follows: Overlapping waves algebraically add to produce a resultant wave. Overlapping waves do not in any way alter the travel of each other. A Interference: The interaction between waves is illustrated in this paragraph. Interference of waves is a result of the principle of superposition. The superposition of waves is mathematically very simple and makes use of known trigonometric relations. You must understand concepts like phase; constructive interference and destructive interference and also know the conditions for both to take place. Derivation 17: Derive equation 16.51 and understand figure 16.14 (16.13 in the 9th edition). See Table 16.1. E Phasors: This is used in advanced work. Read through. D Standing waves: Very interesting application. Standing waves are a special case of superposition of waves that are moving in opposite directions, like waves on a string. The outstanding feature of the resultant standing waves is that there are places along the string where the string never moves. Remember that the two waves that are moving in opposite directions are still present. The standing wave is the resultant of the superposition of the two waves. If any one of the two waves does not exist anymore, so be the standing wave. D Standing waves and Resonance: Very interesting application. This is about standing waves in a string being made to oscillate by an oscillator at the one end. Reflection Review and Summary Individuele aktiwiteit Homework: 13, 31, 42 (10th edition) 5, 13, 10 (9th edition) 44 Study Unit 17 Study unit 17 WAVES II Study material This Study Unit consists of Chapter 17 in the textbook. Study the following attentively The most important concepts in this chapter are: Displacement Amplitude Intensity Pressure amplitude Decibel Interference Beats Wave front Sound level Longitudinal waves Doppler effect Path length difference Mach cone and Mach number Study outcomes After completion of this Study Unit you should be able to: • • • • • define and know the above concepts. use the decibel scale with confidence. describe the superposition of waves mathematically and to determine the end result of such a superposition. describe and know the importance of the Doppler effect. solve simple problems. Study time Contact sessions: 2 hours Self-study: 4 hour 45 Study Unit 17 Important information D What is Physics? Read through B Sound waves: In this chapter we pay attention to longitudinal waves. Sound waves have important medical applications, for example in sonar en physiotherapy treatments. Sound waves are not limited to the earth. They play an important role in outer space in the so called molecular clouds, in supernova explosions etc. B The speed of sound: Speed of a mechanical wave (transversal or longitudinal) depends on the inertial properties of the medium (to store kinetic energy), and the elastic properties (to store potential energy) of the medium. B Travelling sound waves: Like in the case of a transverse wave; it is not the medium that propagates although the medium does oscillate in the direction of propagation. It is only the disturbance that moves through the medium. B Interference: Sound waves undergo interference. Know the conditions for constructive and destructive interference. B Intensity and sound level: Know the definitions of intensity and sound level. Work through Checkpoint 2. E Sources of musical sound: Read through. B Beats: Derivation 18 If sounds of two different frequencies reach our ears simultaneously, then we hear a sound whose frequency is the average of the two combining frequencies. We also hear a striking variation in the intensity of this sound; this is called beats. A The Doppler effect: Derivation 19 The Doppler effect plays an important role, not only in the case of sound waves, but also for transverse waves like electromagnetic waves. Equation 17-47 and its derivation are important. 46 Study Unit 17 B Supersonic speeds, shock waves: Make sure that you know what a Mach number is. Reflection Review and Summary Individual activity Homework: 32, 29, 46 (10th edition) 28, 57, 56 (9th edition) 47 Study Unit 18 Study division F: Study of heat Study unit 18 TEMPERATURE, HEAT AND THE FIRST LAW OF THERMODYNAMICS Study material This Study Unit consists of Chapter 18 in the textbook. Study the following attentively The most important concepts in this chapter are: Thermodynamics Heat capacity Temperature Heat and work Triple point Phase changes Constant volume gas thermometer Heat transfer Thermal expansion Thermodynamic transformations and the first law of thermodynamics Study outcomes After completion of this Study Unit you should be able to: • • • • • • • • 48 know and define the above concepts. explain what is meant by “temperature”. formulate the Zeroth Law of thermodynamics and be able to apply it. explain what is “heat” and the relation between heat and temperature. formulate the relation between heat and work and be able to apply it. apply the First law of Thermodynamics. represent a thermodynamic transformation on a PV diagram. do a variety of problems and applications on thermodynamics. Study Unit 18 Study time Contact sessions: 2 hours Self-study: 4 hour Important information D What is Physics? A few examples of thermodynamics in everyday life are given here. Read through. A Temperature: What is temperature? We normally use this word very easily, but do we really know what we are talking about? By touching two objects, we can say the one is hotter than the other one. This is very subjective and sometimes wrong. It is important to use the correct definition for temperature. A The Zeroth Law of Thermodynamics: Know the law. C Measuring Temperature: A reference temperature is firstly defined in this paragraph and the concept of thermal equilibrium is used then to describe the constant-volume gas thermometer. You must be able to explain the operation of the constant-volume gas thermometer. D Die Celsius and Fahrenheit Scales: Take note of this paragraph because it may be applicable in the problems. In SA we normally do not use the Fahrenheit scale any more. It is still used in the USA for the maximum and minimum day temperatures. C Thermal Expansion: Make sure that you understand the definitions of the coefficients of linear and volume expansion. B Temperature and Heat: Heat is the energy transferred between a system and its environment because of a temperature difference that exists between them. B The absorption of heat by solids and liquids: As seen before, temperature differences between bodies in thermal contact lead to heat transfer. This section deals with the calculation of heat transfer and is thus important. Do Checkpoint 3. 49 Study Unit 18 A Heat and Work: A proper understanding of this section is important for the work that follows. Do Checkpoint 4. A The First Law of Thermodynamics: Know the law and work through Checkpoint 5. B Special cases of the First Law of Thermodynamics: Know the four different thermodynamic processes in table 18.5. C Heat Transfer Mechanisms: The mechanism of heat transfer is discussed here, namely: conduction, convection and radiation. Reflection Review and Summary Individual activity Homework: 61, 58, 4, 25, 40 (10th edition) 9, 28, 22, 45, 48 (9th edition) 50 Study Unit 19 Study unit 19 THE KINETIC THEORY OF GASES Study material This Study Unit consists of Chapter 19 in the textbook. Study the following attentively The most important concepts in this chapter are: Avogadro’s number Equation of state Ideal gas rms speed Universal gas constant Study outcomes After completion of this Study Unit you should be able to: • • understand and define the above concepts. do a variety of problems and applications of the kinetic gas theory. Study time Contact sessions: 2 hours Self-study: 4 hour Important information D What is Physics? This chapter relates the motion of atoms of a gas with the volume, pressure and temperature. Read through 51 Study Unit 19 A Avogadro’s number: One mole of a substance contains Avogadro’s number elementary particles. A Ideal gases: Know the law. Do the first Sample Problem and Checkpoint 1. C Pressure, temperature and rms speed: The pressure exerted by n mole of an ideal gas is given here in terms of the speed of its molecules. C Translational Kinetic energy: The average translational kinetic energy of a gas particle (atom or molecule) is given in terms of the macroscopic temperature, namely: K gem = 3 kT 2 . E Mean Free path: Read through. E The Distribution of molecular speeds: Read through. C The Molar Specific Heats of an Ideal Gas: See notes. E egrees of Freedom and Molar Specific Heats: Read through. E A Hint of Quantum Theory: Read through. C The Adiabatic Expansion of an Ideal Gas: Adiabatic transformations (this is where Q = 0) are very important in lots of classic thermodynamic applications. Note in Figure 19-15; an adiabatic transformation is not isothermal and that an isothermal transformation is not adiabatic. The curve describing an adiabatic transformation on a pV- diagram is given by equation 19-53 and does not follow directly from the equation of state of an ideal gas. 52 Study Unit 19 Reflection Review and Summary Study time Homework: 54, 40, 57 (10th edition) 4, 10, 7 (9th edition) 53 Study Unit 20 Study unit 20 ENTROPY AND THE SECOND LAW OF THERMODYNAMICS Study material This Study Unit consists of Chapter 20 in the textbook. Study the following attentively The most important concepts in this chapter are: Irreversible transformations Entropy Second law of Thermodynamics Efficiency of engines Study outcomes After completion of this Study Unit you should be able to: • understand and define the above concepts and be able to apply it in simple calculations. Study time Contact sessions: 2 hours Self-study: 4 hours Important information D What is Physics? Read through Irreversible Processes and Entropy: Some transformations take place in one direction only and are called irreversible processes. Know the difference between reversible and irreversible processes. Note that only isothermal and adiabatic processes are reversible. This paragraph discusses these transformations and brings in the concept of “entropy”. 54 Study Unit 20 When an irreversible transformation takes place in a closed system, the entropy of the system will always increase, never decrease. A Change in Entropy: The change in entropy is defined in equation 20-1. A Second Law of Thermodynamics: In general it is found in practice that the entropy of a closed system will never decrease during an irreversible process. B Entropy in the Real World: Engines The Carnot engine is important. A heat engine extracts energy from its environment in the form of heat and does useful work. Figure 20-9 shows the pV-diagram of the cycle followed by the working substance (gas) of the Carnot engine Do the two Sample Problems. D Entropy in the Real World: Refrigerators D Die Efficiencies of Real Engines: You must know the definition and be able to apply it. D A Statistical View of Entropy: This section gives a simple introduction to the statistical view of entropy and also how physical systems of particles are described in Statistical Mechanics. Reflection Review and Summary Study time Homework: 36, 46, 1, 43 (10th edition) 4, 6, 25, 27 (9th edition) 55 List of the most important key words List of the most important key words AFRIKAANS 56 ENGLISH Afstand Distance Arbeid Work Arbeid-energiestelling Work Energy Theorem Behoud van energie Conservation of energy Behoud van momentum Conservation of momentum Bewegingsvergelykings Equations of motion Botsing Collision Digtheid Density Dinamika Dynamics Dotproduk (puntproduk) Dot product Druk Pressure Drywing Power Eenheidsvektore Unit vectors Elastiese botsing Elastic collision Elastiese herstelkrag Elastic restoring force Elastiese Potensiële energie Elastic Potential energy Ewewig Equilibrium Gewig Weight Gravitasiekrag Force of Gravity Gravitasie Potensiële energie Gravitational Potential energy Grootte en Rigting Magnitude and Direction Herstelkrag Restoring force Hoekmomentum, hoekposisie, hoeksnelheid hoekverplasing, hoekversnelling Angular momentum, angular position, angular velocity, angular displacement, angular acceleration Horisontale Afstand Range Impuls Impulse Inersiaalsisteem Inertial frame Kinematika Kinematics List of the most important key words Kinetiese energie Kinetic energy Kinetiese Wrywing Kinetic Friction Kinetiese wrywingskoëffisiënt Coefficient of kinetic friction Komponente Components Konserwatiewe Krag Conservative Force Krag Force Kragveld Force Field Kruisproduk Cross product Massamiddelpunt Centre of Mass Meganiese energie Mechanical energy Momentum Momentum Nie-Elastiese botsing Inelastic collision Normaalkrag Normal Force Oombliklike snelheid, oombliklike spoed en oombliklike versnelling Instantaneous velocity, instantaneous speed, and instantaneous acceleration Oppervlakspanning Surface Tension Posisie Position Potensiële energie Potential energy Projektiel Beweging Projectile Motion Relatiewe Beweging Relative Motion Resultant Resultant Rotasie Rotation Sentripetale versnelling Centripetal acceleration Sirkelbeweging Circular motion Skalaar(produk) Scalar(product) Sleurkrag Drag force Snelheid Velocity Spankrag (Spanning) Tension Spoed Speed Statiese Wrywing Static Friction Statiese wrywingskoëffisiënt coefficient of static friction Swaartepunt Centre of Gravity Terminaalsnelheid /spoed Terminal Velocity / speed Traagheidsisteem Inertial Frame of Reference Traagheidsmassa Inertial mass 57 List of the most important key words Traagheidsmoment Moment of inertia Translasiebeweging Translational motion Uniforme sirkelbeweging Uniform circular motion Veerkrag Spring force Vektor(produk) Vector(product) Verplasing Displacement Versnelling Acceleration Vryval Free Fall Wringkrag Torque Wrywing Friction ENGLISH 58 AFRIKAANS Acceleration Versnelling Angular acceleration, angular displacement, angular momentum, angular position, angular velocity Hoekversnelling, hoekverplasing hoekmomentum, hoekposisie, hoeksnelheid Centre of Gravity Swaartepunt Centre of Mass Massamiddelpunt Centripetal acceleration Sentripetale versnelling Circular motion Sirkelbeweging Coefficient of kinetic friction Kinetiese wrywingskoëffisiënt Coefficient of static friction Statiese wrywingskoëffisiënt Collision Botsing Components Komponente Conservation of energy Behoud van energie Conservation of momentum Behoud van momentum Conservative Force Konserwatiewe Krag Cross product Kruisproduk Density Digtheid Displacement Verplasing Distance Afstand Dot product Dotproduk Drag force Sleurkrag Dynamics Dinamika List of the most important key words Elastic collision Elastiese botsing Elastic Potential energy Elastiese Potensiële energie Elastic restoring force Elastiese herstelkrag Equations of motion Bewegingsvergelykings Equilibrium Ewewig Force Krag Force Field Kragveld Force of Gravity Gravitasiekrag Free Fall Vryval Friction Wrywing Gravitational Potential energy Gravitasie Potensiële energie Impulse Impuls Inelastic collision Nie-Elastiese botsing Inertial frame Inersiaalsisteem Inertial Frame of Reference Traagheidsisteem Inertial mass Traagheidsmassa Instantaneous acceleration, instantaneous speed, and instantaneous velocity Oombliklike versnelling, oombliklike spoed en oombliklike snelheid Kinematics Kinematika Kinetic energy Kinetiese energie Kinetic Friction Kinetiese Wrywing Magnitude and Direction Grootte en Rigting Mechanical energy Meganiese energie Moment of inertia Traagheidsmoment Momentum Momentum Normal Force Normaalkrag Position Posisie Potential energy Potensiële energie Power Drywing Pressure Druk Projectile Motion Projektiel Beweging Range Horisontale Afstand Relative Motion Relatiewe Beweging Restoring force Herstelkrag Resultant Resultant 59 List of the most important key words 60 Rotation Rotasie Scalar(product) Skalaar(produk) Speed Spoed Spring force Veerkrag Static Friction Statiese Wrywing Surface Tension Oppervlakspanning Tension Spankrag (Spanning) Terminal Velocity / speed Terminaalsnelheid /spoed Torque Wringkrag Translational motion Translasiebeweging Uniform circular motion Uniforme sirkelbeweging Unit vectors Eenheidsvektore Vector(product) Vektor(produk) Velocity Snelheid Weight Gewig Work Arbeid Work Energy Theorem Arbeid-energiestelling Multilingual key concepts Meertalige kernkonsepte / Multilingual key concepts / Dikakanyokgolo Kernbegrip/Afrikaans Kakanyokgolo ka Setswana Key-concept/English 1 Afstand Distance Sekgala 2 Arbeid Work Tiro 3 Arbeid-energiestelling Work Energy Theorem Tioreme ya TiroMaatla 4 Behoud van energie Conservation of energy Tshomarelo ya maatla 5 Behoud van momentum Conservation of momentum Tshomarelo ya momenthamo 6 Bewegingsvergelykings Equations of motion Ditekano tsa motsamao 7 Botsing Collision Thulano 8 Diffusie Diffusion Phasalalo 9 Digtheid Density Kitlano 10 Dinamika Dynamics Tinamiki 11 Dotproduk Dot product Katisi khutlo 12 Druk Pressure Kgatelelo 13 Drukverskil Gauge Pressure Selekanyi sa kgatelelo 14 Dryfkrag Buoyant Force Thata ya phaphamalo 15 Drywing Power Maatla-a-tiro 16 Eenheidsvektore Unit vectors Dibeketara nngwe 17 Effektiwiteit Efficiency Bokgoni 18 Elastiese botsing Elastic collision Ngaologo ya Thulano 19 Elastiese herstelkrag Elastic restoring force Thata ya pusetso ya ngaologo 20 Elastiese Potensiële energie Elastic Potential energy Ngaologo ya Maatlakgonego 21 Ewewig Equilibrium Tekatekano 22 Gewig Weight Bokete 23 Gravitasiekrag Force of Gravity Maatlakgogedi 24 Gravitasie Potensiële energie Gravitational Potential energy Kgogedi ya Maatlakgonego 25 Grootte en Rigting Magnitude and Direction Bokanakang le Ntlha 26 Herstelkrag Restoring force Thata pusetso 61 Multilingual key concepts 62 27 Hidrouliese Sisteem Hydraulic System Thulaganyo kgatelokedi 28 Hoekmomentum, -posisie, -snelheid -verplasing, versnelling Angular momentum, position, -velocity, displacement, acceleration Momenthamo sekhutlo, kemo, -belosithi, sekgalantlha, -kelolebelo 29 Horisontale Afstand Range Renje 30 Impuls Impulse Imphalese 31 Inersiaalsisteem Inertial frame Kgatlha ya kelolebelotshwano 32 Kinematika Kinematics Kinimatiki 33 Kinetiese energie Kinetic energy Maatlatsamao 34 Kinetiese Wrywing Kinetic Friction Kgotlhanotsamao 35 Kinetiese wrywingskoëffisiënt Coefficient of kinetic friction Khoefišente ya kgotlhanotsamao 36 Komponente Components Dikarolo 37 Konserwatiewe Krag Conservative Force Thata e e khonsebetifi 38 Krag Force Thata 39 Kragveld Force Field Lefelo la thata 40 Kruisproduk Cross product Katiso kgaoganyo 41 Laminêre Vloei Laminar Flow Kelelo e e lamina 42 Massamiddelpunt Centre of Mass Ntlhagare ya Mmase 43 Meganiese energie Mechanical energy Maatla ka motšhini 44 Momentum Momentum Momenthamo 45 Nie-Elastiese botsing Inelastic collision Thulano e e ngaologeng 46 Normaalkrag Normal Force Thata Tlwaelo 47 Oombliklike snelheid, spoed en –versnelling Instantaneous velocity, speed, and –acceleration Belosithi pong, -lebelo, le kelelobelo 48 Oombliklike Versnelling Instantaneous Acceleration Kelebelopong 49 Oppervlakspanning Surface Tension Kgagamalo Boalo 50 Posisie Position Kemo 51 Potensiële energie Potential energy Maatlakgonego 52 Projektiel Beweging Projectile Motion Motsamao wa Sethunngwa 53 Relatiewe Beweging Relative Motion Motsamaomabapi 54 Resultant Resultant Sephethokopanyo 55 Rotasie Rotation Modikologo Multilingual key concepts 56 Sentripetale versnelling Centripetal acceleration Kelolebelo go ya ntlhagareng 57 Sirkelbeweging Circular motion Motsamaotshekeletsa 58 Skalaar(produk) Scalar(product) Sekalara (katisi) 59 Sleurkrag Drag force Thata ya kgogô 60 Snelheid Velocity Belosithi 61 Soortlike Gravitasie Specific Gravity Kgogedi e e rileng 62 Spankrag (Spanning) Tension Kgagamalo 63 Spoed Speed Lebelo 64 Statiese Wrywing Static Friction Kgotlhano-e-e-sa-suteng 65 Statiese wrywingskoëffisiënt coefficient of static friction Khoefišente ya kgotlhano e e sa suteng 66 Swaartepunt Centre of Gravity Ntlhagare ya Maatlakgogedi 67 Terminaalsnelheid /spoed Terminal Velocity / speed Belosithi/lebelo le le khutlang 68 Spoed Uniform circular motion Motsamaotshekeletsa o o sa fetogeng 69 Veerkrag Spring force Thata ya seporeng 70 Vektor(produk) Vector(product) Beketara (katiswa) 71 Verplasing Displacement Sekgalantlha 72 Versnelling Acceleration Kelolebelo 73 Viskose Krag Viscous Drag Kgogô e e kgomarelang 74 Viskositeit Viscosity Go kgomarela 75 Vryval Free Fall Go wa ka kgololosego 76 Wringkrag Torque Maatlatikoloso 77 Wrywing Friction Kgotlhano 63