RI 2024 H2 Physics Promo Sect A QP

RAFFLES INSTITUTION 2024 YEAR 5 PROMOTION EXAMINATION H2 PHYSICS 9749 2 h 30 min RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFL ES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFL ES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFL ES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFL ES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFL ES INSTITUTION Section A INSTRUCTIONS TO CANDIDATES There are 3 sections in this paper. Section A consists of 15 multiple-choice questions. For each question, there are four possible answers A, B, C and D. Choose the one you consider correct and record your choice in soft pencil on the separate Optical Mark Sheet. You are advised to attempt Section A first. The Optical Mark Sheets will be collected after the first 30 minutes. Section B consists of 5 structured questions. You are to write your answers in the spaces provided. Section C consists of 1 data-based question and 1 long structured question. You are to write your answers in the spaces provided. Attempt all questions in Sections A, B and C. There are 9 printed pages, inclusive of the cover page and data & formulae page, in this booklet.

2 © Raffles Institution Data speed of light in free space c = 3.00 × 108 m s−1 permeability of free space 0µ = 4π × 10−7 H m−1 permittivity of free space 0ε = 8.85 × 10−12 F m−1 = (1/(36π)) × 10−9 F m−1 elementary charge e = 1.60 × 10−19 C the Planck constant h = 6.63 × 10−34 J s unified atomic mass constant u = 1.66 × 10−27 kg rest mass of electron me = 9.11 × 10−31 kg rest mass of proton mp = 1.67 × 10−27 kg molar gas constant R = 8.31 J K−1 mol−1 the Avogadro constant NA = 6.02 × 1023 mol−1 the Boltzmann constant k = 1.38 × 10−23 J K−1 gravitational constant G = 6.67 × 10−11 N m2 kg−2 acceleration of free fall g = 9.81 m s−2 Formulae uniformly accelerated motion s = 21 2ut at+ 2v = 2 2u as+ work done on/by a gas W = pV∆ hydrostatic pressure p = ρgh gravitational potential φ = Gm r− temperature T / K = / C 273.15T °+ pressure of an ideal gas p = 21 3 Nm cV mean translational kinetic energy of an ideal gas molecule E = 3 2 kT displacement of particle in s.h.m. x = 0 sinxt ω velocity of particle in s.h.m. v = 0 cosvt ω 22 0xxω= ±− electric current I = Anvq resistors in series R = 12 RR++  resistors in parallel 1/R = 1211 RR++  electric potential V = 4 Q rε0π alternating current/voltage x = 0 sinxt ω magnetic flux density due to a long straight wire B = 0 2 d µ π I magnetic flux density due to a flat circular coil B = 0 2 N r µ I magnetic flux density due to a long solenoid B = 0nµ I radioactive decay x = ( )0 expxt λ− decay constant λ = 12ln2 t

3 © Raffles Institution [Turn over 1 What is the best estimate of the total weight of eight Singapore one-dollar coins? A 0.06 N B 0.6 N C 6 N D 60 N 2 An athlete runs along a straight track. The graph shows the variation of the velocity of the athlete with time for the first 5 s of his run. What is the maximum acceleration and the total distance run during these 5 s? maximum acceleration / m s−2 total distance / m A 2 33 B 2 50 C 6 33 D 6 50 0 2 4 6 8 10 0 1 2 3 4 5 velocity / m s−1 time / s

4 © Raffles Institution 3 A car moving in a straight line at speed u undergoes constant deceleration until it stops. Which graph best represents the variation of the car’s speed v, with distance travelled s, measured from the point it starts decelerating? A B C D 4 A ball of weight w travels with a momentum p and hits a vertical wall at an angle θ to the horizontal. It rebounds at an angle θ as shown. What is the magnitude of the impulse imparted to the wall? A 2p sinθ B 2p sinθ + w C 2p cosθ – w D 2p cosθ v s u 0 0 v s u 0 0 v s u 0 0 v s u 0 0 θ θ p p w ball wall

5 © Raffles Institution [Turn over 5 A crane attempts to lift a sunken cargo box of weight W but is not successful. The magnitude of the force applied by the cable of the crane is T, and the force from the seabed on the box is N. The volume of the seawater displaces by the box has weight S. Which of the following is correct? A W < T + N + S B W = T + N + S C W > T + N + S D W = T + N 6 An escalator is 60 m long and lifts passengers through a vertical height of 30 m as shown. A power of 2.0 kW is needed to drive the escalator against the forces of friction when there are no passengers. The average mass of a passenger is 60 kg and the power required to overcome friction remains constant. What is the power required to drive the escalator when it is traveling at 0.60 m s−1 and carrying 15 passengers? A 2.2 kW B 2.6 kW C 4.3 kW D 4.6 kW cable box seabed seawater 30 m 60 m

6 © Raffles Institution 7 A hydroelectric power station uses the gravitational potential energy of water to generate electrical energy. In one such power station, the mass of water flowing per unit time is 1.5 × 105 kg s−1. The water falls through a vertical height of 120 m. The electrical power generated is 100 MW. What is the efficiency of the power station? A 0.57 % B 43 % C 57 % D 77 % 8 The tip of the hour hand of the clock is 25 cm from the centre of the clock. What is the linear speed of the tip of the hour hand? A 1.8 × 10−5 m s−1 B 3.6 × 10−5 m s−1 C 4.4 × 10−4 m s−1 D 1.3 × 10−1 m s−1 25 cm tip of hour hand

7 © Raffles Institution [Turn over 9 A spherical body P orbit s another spherical body Q. The figure below shows the variation of the gravitational potential φ with distance r from the centre of body P. The minimum amount of energy required to project a 1.0 kg mass from the surface of P to the surface of Q is E. Which of the following is correct? A E < 60 MJ B E = 60 MJ C 60 MJ < E < 140 MJ D 140 MJ < E < 200 MJ 10 A mass of 0.25 kg is suspended from a light spring. When the mass is displaced through a vertical distance of 0.050 m and released, it undergoes simple harmonic motion with a period of 0.64 s. What is the maximum kinetic energy of the mass? A 0.76 mJ B 3.1 mJ C 12 mJ D 30 mJ 11 Which of the following is not an example of forced oscillations? A a footbridge oscillating as people walk on it B a loudspeaker connected to a signal generator producing a continuous note C a pendulum bob oscillating in air after having been initially displaced D a washing machine oscillating as its drum rotates at high speed φ / MJ kg−1 r / m −60 −200 P Q

8 © Raffles Institution 12 A person stands at a distance 3.0 m away from a speaker. The speaker is assumed to be a point source. The effective area of the person's ear is 0.60 cm2 and the power of the sound received by the person’s ear is 2.9 × 10−6 W. What is the power of the speaker? A 1.4 × 10−4 W B 5.5 × 10−4 W C 1.4