Alternative to Practical: answer from the supplied diagrams and data. Upload drawings or graphs where requested; measurements taken from figures should be shown with their workings.
(a)(i)A load of mass M is fixed at the 5.0 cm mark of a metre rule, pivoted at the 50.0 cm mark, as shown in Fig. 3.1. A 50 g movable load balances it. Read both edges of the 50 g load in Fig. 3.2 and determine the position of its centre on the rule.
[2 marks]
(a)(ii)Using your centre position from 3(a)(i), calculate distance d from the centre of the 50 g load to the 50.0 cm pivot in Fig. 3.1. Record d in Table 3.1.
Answer guidance
Using You must use the thing it names. An answer that reaches the right value another way may not score.
[1 mark]
(a)(iii)Calculate 1000 / d from your 3(a)(ii) distance in cm and record it to three significant figures in the first row of Table 3.1, in cm⁻¹.
Answer guidance
Calculate Show your working. The method can earn marks even when the final value is wrong, and a bare answer often cannot.
[2 marks]
(b)It is difficult to balance the metre rule in Fig. 3.1 exactly. Describe a technique to make distance d as accurate as possible.
Answer guidance
Describe Say what happens, in order. Reasons are not required unless the question also asks why.
[1 mark]
(c)Plot m / g on the y-axis against 1000 / d in cm⁻¹ on the x-axis on Fig. 3.3 and draw a straight line of best fit. Table 3.1 prints (m / g, d / cm, 1000 / d in cm⁻¹): (50, blank, blank), (60, 37.7, 26.5), (70, 32.3, 31.0), (80, 28.2, 35.5), (90, 25.3, 39.5), (100, 22.2, 45.0). Fill the 50 g row from your earlier answers. Axes need not begin at zero.
Answer guidance
Complete Fill in every gap. A partly completed answer usually scores partly.
[4 marks]
(d)(i)Calculate the gradient G of your straight best-fit line on Fig. 3.3. Show working and mark on your graph the values used.
Answer guidance
Show The result is given, so every step of the reasoning is what earns the marks.
[2 marks]
(d)(ii)Use your own gradient G from 3(d)(i) and M = 22.2 × G to determine the fixed load mass M, in g.
Answer guidance
Using You must use the thing it names. An answer that reaches the right value another way may not score.
[1 mark]
(e)Explain why the Fig. 3.1 balancing method is unsuitable if the movable load has mass m = 40 g.
Answer guidance
Explain Give reasons, not just what happens. Each distinct reason is usually worth a mark.
[1 mark]
5054/42/M/J/24Cambridge O Level Physics 5054 · May/June 2024 · Paper 4 variant 2 · Question 3