Raffles Institution 2020 Y4 FE Sections A and B

1 Section A [35 marks] Four possible answers A, B, C and D are given for each question. Choose the most appropriate answer and shade your answers in pencil on the OMR answer sheet provided. 1 Which row contains only base quantities? A time, temperature, weight B potential difference, length, mass C charge, temperature, length D amount of substance, current, mass 2 Four students each make a series of measurements of the acceleration due to gravity g. The table shows the results. Which student obtains a set of results that can be described as accurate but not precise? student results, g / m s−2 A 9.81 9.82 9.83 B 8.57 9.79 11.05 C 7.90 8.12 9.25 D 8.47 8.49 8.49 3 A hot air balloon ascends from rest with an acceleration of 2.50 m s −2, in the absence of air resistance. When it reaches a height of 48.0 m above the initial ground level, an object of mass 5.00 kg is released from the balloon. What is the speed of the object just before it impacts the ground? A 28.3 m s−1 B 31.1 m s−1 C 34.4 m s−1 D 35.8 m s−1

2 4 A tennis ball is thrown vertically up, hitting the ceiling before it falls down. Which graph best represents the variation with time t of the velocity v of the ball before and after hitting the ceiling? Assume that the effect of air resistance is negligible. A B C D 5 Which is a scalar quantity? A air resistance B mass C displacement D velocity 6 Three forces, 3.0 N, 4.0 N and 5.0 N are added to obtain a resultant force R. What is the minimum value of R? A 0 N B 2.0 N C 4.0 N D 6.0 N 7 Which situation will friction be classified as a nuisance? A car braking B heat generated when a box is pushed across a rough surface C person holding an object D student walking t t t v v v v 0 0 0 0 t

3 8 A machine is able to lift a solid object with maximum mass of 600 kg on the surface of the earth. The same machine is able to lift another solid object with maximum mass of 3600 kg on the surface of the moon. Why is this so? A The mass of the machine is lesser on the surface of the moon than on the surface of the earth. B The weight of the machine is lesser on the surface of the moon than on the surface of the earth. C The mass of the 3600 kg object is lesser on the surface of the moon than on the surface of the earth. D The weight of the 3600 kg object is lesser on the surface of the moon than on the surface of the earth. 9 A thin square plate has the triangular region A removed. Which region of the plate does the centre of gravity now lie? A B C D

4 0.80 m m / s 10 An uniform thin rod of mass 20.0 g is balanced when a pivot is placed at point