TJC 2022 Prelim P1

TEMASEK JUNIOR COLLEGE 2022 JC2 PRELIMINARY EXAMINATION Higher 2 CANDIDATE NAME CENTRE NUMBER S INDEX NUMBER PHYSICS 9749/01 Paper 1 Multiple Choice 15 September 2022 1 hour Additional Materials: Multiple Choice Answer Sheet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name and Civics group on the Answer Sheet in the spaces provided. There are thirty questions in this paper. Answer all 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 Answer Sheet. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. Any rough working should be done in this booklet. The use of an approved scientific calculator is expected, where appropriate. Do NOT open the booklets until you are told to do so. This booklet consists of 14 printed pages.

2 Data speed of light in free space c = 3.00  108 m s−1 permeability of free space 0 = 4   10−7 H m−1 permittivity of free space 0 = 8.85  10−12 F m−1 = (1/(36))  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 21 2s ut at=+ 22 2v u as=+ work done on / by a gas W = pV hydrostatic pressure p = gh gravitational potential temperature T/K = T/C + 273.15 pressure of an ideal gas 21 3 Nmpc V= mean translational kinetic energy of an ideal gas molecule 3 2E kT= displacement of particle in s.h.m. velocity of particle in s.h.m. electric current I = Anvq resistors in series R = R1 + R2 + . . . . resistors in parallel 1/R = 1/R1 + 1/R2 + . . . . electric potential V = Q/(40r) alternating current / voltage x = x0 sint magnetic flux density due to a long straight wire magnetic flux density due to a flat circular coil magnetic flux density due to a long solenoid radioactive decay x = x0 exp(−t) decay constant Gm r =− 0 sinx x t = 0 cosv v t = 22 0xx=  − 0 2B d  = I 0 2 NB r = I 0Bn = I 1 2 ln 2 t =

3 [Turn over 1 The drag coefficient Cd is a number with no units. It is used to compare the drag on different cars at different speed. Cd is given by the equation 2 d n FC vA= where F is the drag force on the car,  is the density of the air, A is the cross-sectional area of the car and v is the speed of the car. What is the value of n ? A 1 B 2 C 3 D 4 2 The radius of the Earth is approximately 6.4106 m, and the radius of the moon is approximately 1.7106 m. A student wishes to build a scale model of the Solar System in the classroom, using a football of radius 0.12 m to represent the Earth. Which object would best represent the Moon? A basketball B cherry C golf ball D tennis ball 3 A passenger in a car travelling due East at speed vC sees a motorcyclist travelling due North−West at speed vM. Which diagram shows the velocity vR of the motorcyclist relative to the passenger in the car? A B C D North vM vC vC vM vR vC vM vR vC vM vR vC vM vR

4 4 Two small identical objects P and Q are released from rest from the top of a building 80 m above the ground. Q is released 1.0 s after P. Neglecting air resistance, what is the maximum vertical separation between P and Q in the air? A 5.0 m B 10 m C 35 m D 45 m 5 A small object at O is kept in static equilibrium by a horizontal thread OA and a light spring OB which makes an angle  with the vertical as shown below. If the thread is suddenly cut, what are the direction and magnitude of the acceleration of the object at that instant? Direction Magnitude A I g sin B I g tan C II g sin D II g tan 6 The above figure shows an open wagon moving with negligible resistance in vertically falling rain. An appreciable amount of rain falls into the wagon and accumulates there. What are the effects of the accumulating rain on the speed, momentum and kinetic energy of the wagon? (Ignore the effects of the raindrops hitting the front of the wagon.) speed momentum Kinetic energy A decrease unchanged unchanged B decrease unchanged decrease C decrease decrease decrease D unchanged unchanged Unchanged B  O II I A

5 [Turn over 7 An uneven rod is supported from a peg by means of a string. The friction force between the peg and the string is negligible. Which of the points best shows the position of the centre of gravity of the rod? 8 The force diagram shows an aircraft accelerating. At the instant shown, the velocity of the aircraft is 40 m s-1. At what rate is its kinetic energy increasing? A 2.4 MW B 8.0 MW C 12 MW D 20 MW 9 The figure shows a pendulum bob swinging between positions x and y. Which of the arrows P, Q, R, S represents the direction of the resultant force acting on the bob when the bob is at position z? (Neglect air resistance.) A P B Q C R D S y x z P S R Q

6 10 A car is travelling on a road in hilly terrain, as shown in diagram below. The tops and bottoms of the hill have radius of curvature R. Assuming that the car is moving with a speed v, at which point of the hill and at what speed is the driver of the car most likely to feel weightless? A at the top of a hill when v gR B at the bottom of a hill when v gR C at the top of a hill when v gR D at the bottom of a hill when v gR 11 Four planets A, B, C and D have masses and radii as listed in terms of M and R where M and R are the mass and radius of the Earth respectively. Which planet would have a surface escape speed which is the same as that of the Earth? mass of planet radius of planet A M2 1 R 2 1 B M2 1 R C M R2 1 D 2M 2R 12 An external agent does 50 J of work in moving a mass of 2.0 kg from point A to point B in a gravitational field, and −60 J of work in moving the mass from point B to point C. Finally, the external agent does work of 1000 J in moving the mass from point C to infinity. What is the gravitational potential at point A? A −555 J kg−1 B −505 J kg−1 C -495 J kg−1 D -445 J kg−1

7 [Turn over 13 To cool down the electrical generator of a nuclear power plant, cold water enters the heat exchanger of the generator at 3 °C and leaves at 11 °C. T he rate of heat removed by the water is 11 J per 4.0 0 .1 hour The specific heat capacity of water is 4200 J kg−1 K−1. What is the rate of water flow? A 11 14.0 10 4200 8 60 60 kg s −    B 11 14.0 10 60 60 4200 8 kg s−    C 11 14.0 10 4200 kg s 8 60 −  D 11 14.0 10 60 42 kg00 8 s−  14 Some sand is placed on a flat horizontal plate and the plate is made to oscillate with simple harmonic motion in a vertical x-direction, as shown. The amplitude of oscillation xo of the plate is such that the maximum acceleration is equal to th