EJC 2024 J2 H2 PRELIM QP P4

©EJC 2024 9749/04/J2H2Prelim/2024 [Turn over EUNOIA JUNIOR COLLEGE JC2 PRELIMINARY EXAMINATIONS 2024 General Certificate of Education Advanced Level Higher 2 CANDIDATE NAME CIVICS GROUP 2 3 - REGISTRATION NUMBER PHYSICS Paper 4 Practical 9749/04 August 2024 2 hours 30 minutes Candidates answer on the Question Paper. Additional Materials: As listed in the Confidential Instructions READ THESE INSTRUCTIONS FIRST Write your name, civics group and registration number in the spaces at the top of this page. Write in dark blue or black pen on both sides of the paper. You may use an HB pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, glue or correction fluid. Answer all questions. Write your answers in the spaces provided on the question paper. The use of an approved scientific calculator is expected, where appropriate. You may lose marks if you do not show your working or if you do not use appropriate units. Give details of the practical shift and laboratory, where appropriate, in the boxes provided. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. This document consists of 20 printed pages and 4 blank pages. Shift Laboratory For Examiner’s Use 1 10 2 12 3 22 4 11 Total 55

2 ©EJC 2024 9749/04/J2H2Prelim/2024 1 In this experiment, you will investigate the effect of friction on a simple pulley system. (a) You are provided with a spring of unstretched length 0L , as shown in Fig. 1.1. Fig. 1.1 Measure and record 0L . 0L = (b) Set up the apparatus as shown in Fig. 1.2. Fig. 1.2 Ensure that the pipe remains horizontal at all times, and that the strings on each side of the pipe are vertical and parallel with each other. The spring should only stretch minimally at this instant. L0 string mass hanger spring retort stand boss clamp clamp bench PVC pipe boss string G-clamp

3 ©EJC 2024 9749/04/J2H2Prelim/2024 [Turn over (i) Place the 100 g slotted mass onto the mass hanger and slowly lower the mass hanger, allowing the spring to extend to a new equilibrium length 1L , Measure and record 1L . 1L = [1] Calculate the extension 1x of the spring from its unstretched length, where 1 1 0x L L=− 1x = [1] (ii) Estimate the percentage uncertainty in your value of 1x . percentage uncertainty in 1x = [2]

4 ©EJC 2024 9749/04/J2H2Prelim/2024 (iii) Pull the mass hanger downwards by about 20 cm, causing the spring to extend further. Hold the hanger while allowing it to slowly rise upwards until the spring retracts to another equilibrium length 2L , where 2L is larger than 1L . Measure and record 2L . 2L = Calculate the new extension 2x of the spring from its unstretched length, where 2 2 0x L L=− 2x = [1]

5 ©EJC 2024 9749/04/J2H2Prelim/2024 [Turn over (c) Theory suggests that 1x and 2x are related by the expression 2 1 ln 2x x = where  is a constant. (i) Using your answers to (b)(i) and b(iii), determine a value for .  = [1] (ii) The experiment is repeated with different numbers of slotted masses to obtain more values of 1x and 2x . State how a straight-line graph can be plotted and used to determine the value of , assuming the theory is correct. [2] (iii) State the value of  if the pipe is frictionless. Explain your answer. [2] [Total: 10]

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7 ©EJC 2024 9749/04/J2H2Prelim/2024 [Turn over 2 In this experiment, you will investigate the period of a conical pendulum. Tie one end of the string to the pendulum bob. Place the short plastic ruler on a flat surface such as the top of your stool, bench or floor. Hold the pendulum directly above one end of the ruler. The length L from the point where you are holding the string to the centre of the bob should be approximately 50 cm. Gently swing the pendulum so that the bob performs uniform circular motion just above the ruler, as shown in Fig. 2.1. Fig. 2.1 The position of your eye should be vertically above the point where you are holding the string, and the end of the ruler, which is located at the centre of the circular motion. Maintain the position of your eye and the point of suspension of the pendulum. Swing the pendulum continually so that the radius r of the circular motion about 10 cm. (You may want to use a pencil or a pen to point to the desired r value on the rule r for easy reference as you conduct the experiment.) The period of the conical pendulum is T. r L small plastic ruler pendulum bob position of eye flat surface circular path of bob

8 ©EJC 2024 9749/04/J2H2Prelim/2024 (a) (i) Measure and record r and L. Determine and record T. r = L = T = [1] (ii) Estimate the percentage uncertainty in your value of r. percentage uncertainty in r = [1] (b) Keeping r constant at 10 cm, determine T for three more values of L, where 20 cm  L  50 cm. Tabulate your results. [3]

9 ©EJC 2024 9749/04/J2H2Prelim/2024 [Turn over (c) T and L are related by the expression: 42T AL B=− where A and B are constants. Plot a suitable graph on the grid below to determine A. A = [3]

10 ©EJC 2024 9749/04/J2H2Prelim/2024 (d) Theory suggests that: 4 2 16A g = where g is the acceleration of free fall. Using your answer to (c), determine a value for g. g = m s−2 [1] (e) The average value for g is 9.81 m s−2. Show whether your value in (a)(ii) explains the difference between the value of g you have determined in (d) and the average value for g of 9.81 m s−2. [2] (f) It is further suggested that the ratio: 2B rA = Using this expression, and the expressions provided in (c) and (d), sketch a line on your graph grid in (c) to show the expected result if the experiment is repeated on the moon. Label this line M. [1] [Total: 12]