SENIOR HIGH SCHOOL General Physics1 Quarter 1 – Module 1: Title: Measurements Science – Grade 12 Alternative Delivery Mode Quarter 1 – Module 1: Measurements First Edition, 2020 Republic Act 8293, section 176 states that: No copyright shall subsist in any work of the Government of the Philippines. However, prior approval of the government agency or office wherein the work is created shall be necessary for exploitation of such work for profit. Such agency or office may, among other things, impose as a condition the payment of royalties. Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names, trademarks, etc.) included in this module are owned by their respective copyright holders. Every effort has been exerted to locate and seek permission to use these materials from their respective copyright owners. The publisher and authors do not represent nor claim ownership over them. Published by the Department of Education Secretary: Leonor Magtolis Briones Undersecretary: Diosdado M. San Antonio Development Team of the Module Writer: Loida A. Arce Editor: Jacqueline T. Ureta Reviewer: Alma D. Acuña Illustrator: Name Layout Artist: Name Management Team: Dr. Carlito D. Rocafort Dr. Job S. Zape Jr. Eugene Adrao Elaine Balaogan Dr. Elpidia B. Bergado Noel S. Ortega Dr. Josephine Monzaga Printed in the Philippines by ________________________ Department of Education – Region IV-A Office Address: Telefax: E-mail Address: Capitol Compound, Brgy. Luciano Trece Martires City, Cavite (046) 419 139 / 419-0328 depedcavite.lrmd@deped.gov.ph 12 General Physics1 Quarter 1 – Module 1: Measurements Introductory Message For the learner: Welcome to the General Physics 1 12 Alternative Delivery Mode (ADM) Module. The hand is one of the most symbolized part of the human body. It is often used to depict skill, action and purpose. Through our hands we may learn, create and accomplish. Hence, the hand in this learning resource signifies that you as a learner is capable and empowered to successfully achieve the relevant competencies and skills at your own pace and time. Your academic success lies in your own hands! This module was designed to provide you with fun and meaningful opportunities for guided and independent learning at your own pace and time. You will be enabled to process the contents of the learning resource while being an active learner. This module has the following parts and corresponding icons: What I Need to Know This will give you an idea of the skills or competencies you are expected to learn in the module. What I Know This part includes an activity that aims to check what you already know about the lesson to take. If you get all the answers correct (100%), you may decide to skip this module. What’s In This is a brief drill or review to help you link the current lesson with the previous one. What’s New In this portion, the new lesson will be introduced to you in various ways such as a story, a song, a poem, a problem opener, an activity or a situation. What is It This section provides a brief discussion of the lesson. This aims to help you discover and understand new concepts and skills. What’s More This comprises activities for independent practice to solidify your understanding and skills of the topic. You may check the answers to the exercises using the Answer Key at the end of the module. What I Have Learned This includes questions or blank sentence/paragraph to be filled in to process what you learned from the lesson. What I Can Do This section provides an activity which will help you transfer your new knowledge or skill into real life situations or concerns. Assessment This is a task which aims to evaluate your level of mastery in achieving the learning competency. Additional Activities In this portion, another activity will be given to you to enrich your knowledge or skill of the lesson learned. This also tends retention of learned concepts. At the end of this module you will also find: References This is a list of all sources used in developing this module. The following are some reminders in using this module: 1. Read the instruction carefully before doing each task. 2. Observe honesty and integrity in doing the tasks. 3. Finish the task at hand before proceeding to the next. If you encounter any difficulty in answering the tasks in this module, do not hesitate to consult your teacher or facilitator. Always bear in mind that you are not alone. We hope that through this material, you will experience meaningful learning and gain deep understanding of the relevant competencies. You can do it! What I Need to Know This module was designed and written with you in mind. It is here to help you master the measurements. The scope of this module permits it to be used in many different learning situations. The language used recognizes the diverse vocabulary level of students. The lessons are arranged to follow the standard sequence of the course. But the order in which you read them can be changed to correspond with the textbook you are now using. The module has one lesson, namely: • Lesson 1 – Least Concept to Estimate Error After going through this module, you are expected to: 1. Use the least count concept to estimate errors associated with single measurements. Lesson 1 Measurement It is important to be honest when reporting a measurement, so that it does not appear to be more accurate than the equipment used to make the measurement allows. We can achieve this by controlling the number of digits, or significant figures, used to report the measurement. Measurement values are only as accurate as the measurement equipment used to collect them. For example, measuring meters with a meter stick is rather accurate; measuring millimeters (1/1,000 of a meter) with a meter stick is inaccurate. Using significant figures helps prevent the reporting of measured values that the measurement equipment is not capable of determining. A significant figure is comprised of the fewest digits capable of expressing a measured value without losing accuracy. As the sensitivity of the measurement equipment increases, so does the number of significant figures. Knowing the rules for working with significant figures can help your students. “Rounding” numbers is the usual method of achieving significant figures. Once the appropriate number of significant figures for any measurement, calculation, or equation is determined, students can practice rounding their answers appropriately. What’s In Compare and contrast accuracy and precision; random and systematic error. What’s New To determine the number of significant figures in a number use the following 3 rules: 1. Non-zero digits are always significant 2. Any zeros between two significant digits are significant 3. A final zero or trailing zeros in the decimal portion ONLY are significant Example: .500 or .632000 the zeros are significant .006 or .000968 the zeros are NOT significant For addition and subtraction use the following rules: 1. Count the number of significant figures in the decimal portion ONLY of each number in the problem 2. Add or subtract in the normal fashion 3. Your final answer may have no more significant figures to the right of the decimal than the LEAST number of significant figures in any number in the problem. For multiplication and division use the following rule: 1. The LEAST number of significant figures in any number of the problem determines the number of significant figures in the answer. (You are now looking at the entire number, not just the decimal portion) *This means you have to be able to recognize significant figures in order to use this rule* Example: 5.26 has 3 significant figures 6.1 has 2 significant figures What is It Rules for Significant Figure 1. All non-zero numbers ARE significant. The number 33.2 has THREE significant figures because all of the digits present are non-zero. 2. Zeros between two non-zero digits ARE significant. 2051 has FOUR significant figures. The zero is between a 2 and a 5. 3. Leading zeros are NOT significant. They're nothing more than "place holders." The number 0.54 has only TWO significant figures. 0.0032 also has TWO significant figures. All of the zeros are leading. 4. Trailing zeros to the right of the decimal ARE significant. There are FOUR significant figures in 92.00. 92.00 is different from 92: a scientist who measures 92.00 milliliters knows his value to the nearest 1/100th milliliter; meanwhile his colleague who measured 92 milliliters only knows his value to the nearest 1 milliliter. It's important to understand that "zero" does not mean "nothing." Zero denotes actual information, just like any other number. You cannot tag on zeros that aren't certain to belong there. 5. Trailing zeros in a whole number with the decimal shown ARE significant. Placing a decimal at the end of a number is usually not done. By convention, however, this decimal indicates a significant zero. For example, "540." indicates that the trailing zero IS significant; there are THREE significant figures in this value. 6. Trailing zeros in a whole number with no decimal shown are NOT significant. Writing just "540" indicates that the zero is NOT significant, and there are only TWO significant figures in this value. 7. Exact numbers have an INFINITE number of significant figures. This rule applies to numbers that are definitions. For example, 1 meter = 1.00 meters = 1.0000 meters = 1.0000000000000000000 meters, etc. So now back to the example posed in the Rounding Tutorial: Round 1000.3 to four significant figures. 1000.3 has five significant figures (the zeros are between non-zero digits 1 and 3, so by rule 2 above, they are significant.) We need to drop the final 3, and since 3 < 5, we leave the last zero alone. so 1000. is our four-significant-figure answer. (from rules 5 and 6, we see that in order for the trailing zeros to "count" as significant, they must be followed by a decimal. Writing just "1000" would give us only one significant figure.) 8. For a number in scientific notation: N x 10x, all digits comprising N ARE significant by the first 6 rules; "10" and "x" are NOT significant. 5.02 x 104 has THREE significant figures: "5.02." "10 and "4" are not significant. Rule 8 provides the opportunity to change the number of significant figures in a value by manipulating its form. For example, let's try writing 1100 with THREE significant figures. By rule 6, 1100 has TWO significant figures; its two trailing zeros are not significant. If we add a decimal to the end, we have 1100., with FOUR significant figures (by rule 5.) But by writing it in scientific notation: 1.10 x 103, we create a THREE-significant-figure value. What I Have Learned 1. Significant figures of a measured or calculated quantity are the meaningful digits in it. 2. Any digit that is not zero is significant. 3. Zeros between non-zeros digits are significant. 4. Zeros to the left of the first non-zero digit are not significant. 5. For numbers with decimal points, zeros to the right of a non-zero digit are significant. References Chhetri, Khadka Bahadur. Computation of Errors and their Analysis on Physics Experiments. Tribhuvan University, Nepal. Giancoli. Physics 215: Experiment 1 Measurement, Random Error, Error Analysis. Sio, Janina Andrea et.al. Experiments: Errors, Uncertainties and Measurements Laboratory Report. Manila, Philippines. Tabujara Jr., Geronimo D. K-12 Compliant Worktext for Senior High School General Physics 1. Manila, Philippines: JFS Publishing Services For inquiries or feedback, please write or call: Department of Education - Bureau of Learning Resources (DepEd-BLR) Ground Floor, Bonifacio Bldg., DepEd Complex Meralco Avenue, Pasig City, Philippines 1600 Telefax: (632) 8634-1072; 8634-1054; 8631-4985 Email Address: blr.lrqad@deped.gov.ph * blr.lrpd@deped.gov.ph