2023 Physics Prelim Paper 3 Mark Scheme

14 August 2023 1 hour 50 minutes Anglican High School Secondary Four Preliminary Examination 2023 CLASS CLASS INDEX 4 Anglican High School 2023_S4_Prelim_PHY_P3 [Turn over S4 This document consists of 12 printed pages.

1 In this experiment, you will investigate the mass and volume of a brass mass. You are provided with: • a brass mass Note: Deduct max 1m for precision error(s) and max 1m for unit error (s) • a ruler • two set squares • an electronic balance (a) (i) Describe one precaution you must take before measuring the mass of the brass mass using an electronic balance. …Press the ‘0’ or tare button to ensure that the initial reading is 0.00 g. ………. [1] (ii) Measure and record the mass of the brass mass. Between 99.00 g to 101.00 g (to 2 d.p.) mass = ……………………………. [1] (b) (i) Draw a labelled diagram to show how to use the ruler and the set squares to measure the diameter of the brass mass. correct use of set squares (to determine the boundary of the diameter) and use of rule to measure the diameter [1] (Note: The 30-cm ruler’s zero mark is not at the edge. Not all set squares have the zero mark at the edge) correct labelling of mass, set squares and ruler [1] (provided the set-up is correct) (ii) Measure and record the diameter d of the brass mass. d = 2.5 cm to 2.7 cm to 1 d.p.[1] d = ……………….………. [1] 2 Section A ruler set squares diameter

(c) (i) Measure and record the total length l of the brass mass, as shown in Fig. 1.1. 2.8 cm – 3.4 cm [1] in 1 d.p Fig. 1.1 (not to scale) l = ………………………….. [1] (ii) Estimate the volume V of the brass mass using the equation 𝑉 = 𝜋 4 𝑙𝑑2 Correct calculations with correct units (cm3) [1] (14 to 19 cm3) V = ……………………….… [1] (iii) The volume calculated in (c)(ii) is an estimate of the volume of the brass mass. Explain why it is only an estimate and whether it is a good or poor estimate of the actual volume of the brass mass. Why it is an estimate: length included spaces occupied by air / uneven diameter throughout the length [1] Why it is a poor estimate: Poor estimate of actual volume of brass mass as the volume of air is of a significant percentage of volume calculated in c(ii) / the difference was very large compared to the total volume [1] (iv) Describe how the method for determining the volume of the brass mass may be improved. Use displacement method to find volume of brass mass from the change in volume of water in measuring cylinder [1] Or Measure volume of water displaced from a Eureka can when mass is placed inside [1] Or Usi