CONTINOUS ASSESMENT LEARNING ACTIVITY (CALA). Name: ………………………………………………………… School:………………………………………………………… Class:…………………………………………………………… Candidate Number:……………………………………… LEARNING AREA: PHYSICS LEVEL: A’LEVEL CALA TYPE: RESEARCH, DATA COLLECTION, DESIGNING, EXPERIMENTING, PEN AND PAPER. SYLLABUS TOPIC: KINEMATICS SYLLABUS SUB-TOPIC: ACCELERATION DUE TO GRAVITY. CALA TITLE: DETERMINATION OF ACCELERATION TO GRAVITY EXPERIMENTALY. COMPETENCE /SKILLS: IDENTIFYING A PROBLEM, INVESTIGATING, DESIGNING, EXPERIMENTING, OBSERVING, DATA COLLECTION, RECORDING, ANALYSING AND DRAWING. BACKGROUND: During wars and military operations, wrong targets have been attacked by missiles due to errors associated with failing to determine the size of the air resistance and the varying values of the Earth’s gravitational acceleration. Assuming that the gravitational acceleration, g = 9.81m/s2 in all places on Earth has led to erroneous calculations which have caused missiles to bomb wrong targets. TASK As an A‘level Physics student you are supposed to design and carry out an Experiment to determine the value of the Gravitational Acceleration at your school after which you will make a comparison between the theoretical value [g=9.81m/s2] to the value you will obtain. This CALA is divided into three parts which are: PART-A PART-B PART-C This CALA is marked out of 85 and the final score/mark obtained will be expressed as a percentage. LEARNER CALA GUIDE PART-A (DESIGN OF EXPERIMENT) You are provided with the following Apparatus: Pendulum bob, 1m string, Retort Stand, Stop Watch, Protractor, Meter rule, Micrometre screw gauge, Sticky stuff and a Permanent Marker. PART-A Objectives: Identify the Apparatus provided in this CALA and recall how they are used. Design an Experiment and clearly draw a fully labelled diagram of how you will arrange the apparatus. State the role play of each of the Apparatus stated above. Identify five weaknesses of your design. PART A Questions: 1. Theory Suggests that, 𝑻 = 𝟐𝛑√(𝐼/𝒈) ,where T is the Period of Oscillation, I is the length of the pendulum and g is the gravitational acceleration. You are to show that T2 = 4π2l/g and relate this equation to the linear equation (y = mx + c) and identify the following parameters from the equation (T2 = 4π2l/g): i. The y-variable [2 Marks] …………………………………………………………………………………………………………… ………………………………………………………………………………………………………….. ii. The x-variable [2Marks] …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… iii. The Gradient [2Marks] …………………………………………………………………………………………………………… ………………………………………………………………………………………………………….. iv. The y-intercept [2 Marks] …………………………………………………………………………………………………………… ………………………………………………………………………………………………………….. [2 Marks] 2. You are provided with the following Apparatus: Pendulum bob, 1m string, Retort Stand, Stop Watch, Protractor, Meter rule, Micrometre screw gauge, Sticky stuff and a Permanent Marker: You are to design and Experiment to determine the value of the Gravitational Field strength/Gravitational Acceleration (g) using all or some of the apparatus provided. Your design should include the following details. i. A fully labelled diagram of the Apparatus set up for the experiment. ii. [7 Marks] A detailed description of the procedure to be followed during the Experiment. …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… ………………………………………………………………………………………………………….. [12Marks] iii. Evaluate your design and state any 5 shortfalls (5 possible sources of error) of the design you created. …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… ………………………………………………………………………………………………………….. [5 Marks] PART-B (Experimenting) To Carry out the experiment, you are provided with the experiment’s practical procedure. Follow the instructions and record your results in the following table. TABLE OF RESULTS Length of Pendulum l/m Time for 10 Oscillations; t1/s; t2/s; t3/s; Average time/s; Period T/s; (Period)2 T2/s2; [30 Marks] PART –C 1. Using the Data you obtained from Component B (Experiment), plot a graph of T2 against l. A graph paper has been provided for this Question. [7Marks] 2. Using your graph, determine the value of T2 when I = 0.35m. T 2 = …………………..…… [3 Marks] 3. Use your graph in question 2 to calculate the Gradient of the graph. Gradient = ………………………. [6 Marks] 4. Theory suggests that T2 = 4π2l/g, and when this equation is compared to the linear equation, y =mx + c, the expression 4π2/g is equivalent to the value of the Gradient. From this equation 4π2/g = Gradient, calculate the value of g (gravitational acceleration). g = …………………….. [4 Marks] 5. The theoretical value of the gravitational acceleration g = 9.81m/s2. Compare this value with the one you obtained in question 4 and give five reasons for the differences between the theoretical value (9.81m/s2) and the value you obtained in your experiment. 1………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………… 2………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………… 3………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………….. 4………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………… 5………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………… [10 Marks]
