SCGS 2025 PHY PRELIM P3 MS

1 1 To investigate the force needed to pull a cylinder up a step. Qn Marking criteria Mark Remark 1(a) Evidence that more than one measurement is made and average calculated. Correct d.p. of measured/average value* 1 No mark awarded if BOTH criteria are not evident Mark awarded for correct d.p and with correct unit 1(b)(ii) Correct d.p. of measured value. 1 1(c) Evidence that more than one measurement is made and average calculated Radius r determined 1 No mark awarded if BOTH criteria are not evident Working optional 1(d)(i) Correct d.p. of measured value. 1 1(d)(ii) Angle  calculated. Working shown. 1 PLAN ▪ Independent, dependent variable ▪ one measurable controlled variable given ▪ Detail instructions on how the experiment is carried out to investigate relationship including instructions of how accurate results are achieved and instructions on tabulation and graph to be sketched. ▪ Explanation on how to reach conclusion from sketched graph. 1 1 2 1 Award mark for only for all three correct variables given Total 10 *all readings are expected to have the correct unit

2 Independent variable: mass, m Dependent variable: applied force, F Controlled variable: Height of string loop above the benchtop; loop parallel to ½ metre rule; newton meter parallel to benchtop. Procedure 1. Measure the mass each of the circular weight using the digital balance. Record the reading as m. 2. Take corresponding measurements for the diameter of the circular weight. Determine its radius r. 3. Measure the height h of the ½ metre rule using a vernier caliper. Determine the average height, have. 4. Set up the experiment as shown in Fig. 1.3 5. Pull the mass and ensure that the string is taut. 6. Measure the height of the string loop above the bench top. This height is to be measured and remain constant for every repeated measurement of the applied force. 7. View the string loop and the newton meter from the top. Ensure that both are aligned parallel to the benchtop. 8. Increase the applied force slowly until the mass is just about to roll up the edge of the ruler. Note the newton meter reading, F. 9. Repeat 4 to 8 to obtain another reading for F. Determine the average force applied, Fave. 10. Repeat steps (6) and (7) to obtain five other values of Fave . 11. Tabulate all readings. Convert the mass to kg. Include Reading m/kg F1/N F2/N Fave/N 1 2 3 4 5 12. Plot a graph of Fave against m. 13. Determine the gradient of the graph. 14. The equation is re-written as 𝑭 = 𝒌𝒎𝒈 𝐭𝐚𝐧 𝜶 where g = 10 N/kg is the acceleration due to gravity 15. A graph of Fave against m is expected to yield a straight line passing through the origin with gradient. 𝒌𝒈 𝒕𝒂𝒏 𝜶 Fave / N