Raffles Institution 2019 Y4 FE Sections A and B

1 Section A [30 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 OTAS answer sheet provided. 1 Which option consists of a pair of SI base unit? A ampere joule B newton second C kilogram kelvin D metre coulomb 2 A box is dropped from a tall building. As the box falls, air resistance has a noticeable effect on its motion. Graph 1 Graph 2 Graph 3 How many graph(s) correctly describe(s) the motion of the box from time 0 s to time t? A 0 B 1 C 2 D 3 3 An object is moving with an initial velocity of 6.0 m s−1 to the right when it undergoes acceleration for a duration of 6.0 s as shown. Take displacement to the right as positive. What is the velocity of the object after 6.0 s? A −2.0 m s−1 B 2.0 m s−1 C 4.0 m s−1 D 8.0 m s−1 1.0 −4.0 a / m s−2 t / s 0 1.0 2.0 3.0 4.0 5.0 6.0 displacement / m time / s 0 t acceleration / m s−2 time / s 0 t velocity / m s−1 time / s 0 t

2 4 Forces of 3.0 N and 6.0 N act at a point. Which vector diagram shows a resultant of 6.0 N? A B C D 5 When a metal ball of weight W is placed inside a beaker of water, the newton-balance reads X. When the immersed metal ball is suspended by a spring-balance, the newton-balance reads Y. What is the reading of the spring balance? A X − W B X − Y C Y − W D Y spring-balance newton-balance Y X newton-balance metal ball in a beaker of water 3.0 N 6.0 N 3.0 N 6.0 N 3.0 N 6.0 N 3.0 N 6.0 N

3 6 A clown on a unicycle accelerates to the right as shown. What is the direction of the frictional force acting on the wheel? A B C D 7 An L-shaped bar of uniform density and uniform cross-sectional area is hung on a frictionless pin P at its right-angle corner as shown. The lengths of the sides are x and 2x respectively. What is the angle θ that the shorter arm makes with the vertical? A 14° B 27° C 63° D 76° 8 An object of mass 2.0 kg is falling at a speed of 3.00 m s -1 at one particular instant. It experiences an average resistive force of 1.0 N as it falls . What is the gain in kinetic energy of the object after it falls a further distance of 15.0 m? A 279 J B 288 J C 294 J D 303 J 9 A scientist is shown a collection of electric cars. He is provided with only four measuring instruments and tasked to determine which of the cars has the greatest power. Which instrument will be the least useful to the scientist? A industrial weighing scale B speedometer C stopwatch D voltmeter P θ 2x x acceleration wheel road

4 10 Which information cannot be determined from the displacement-time graph of a wave? A amplitude B frequency C period