2013 NYJC H2 Physics P1 QP

NANYANG JUNIOR COLLEGE  Science Department  JC 2 PRELIMINARY EXAMINATION  Higher 2  PHYSICS  9646/01 Paper 1   Multiple Choice  18 September 2013    1 hour 15 minutes  Additional Materials : Multiple Choice Answer Sheet  READ THESE INSTRUCTIONS FIRST     Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your  name, Centre number and index number on the Answer Sheet in the spaces provided unless this has  been done for you.    There are TWENTY‐TWO questions on 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.     Read the instructions on the Answer Sheet very carefully.     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.  This document consists of 9 printed pages    Nanyang Junior College

2 Data Formulae uniformly accelerated motion, s = ut + ½at2 v2 = u2 + 2as work done on/by a gas, W = p∆V hydrostatic pressure, p = Ρgh gravitational potential,  = /Gm r displacement of particle in s.h.m. x = xo sin ωt velocity of particle in s.h.m. v = vo cos ωt =  22 xxo  mean kinetic energy of a molecule of an ideal gas E = 3 2 kT resistors in series, R = R1 + R2 + … resistors in parallel, 1/ R =1 / R1 + 1/R2 + … electric potential, V = Q / 4πεor alternating current/voltage, x = xo sin ωt transmission coefficient, T α exp(-2kd) where k =  2 2 8 mU E h   radioactive decay, x = xo exp (-λt) decay constant λ = 21 693.0 t speed of light in free space, c = 3.00 x 10 8 m s-1 permeability of free space, μo =4 π x 10-7 H m-1 permittivity of free space, εo = 8.85 x 10 -12 Fm-1 (1 / (36 π)) x 10-9 Fm-1 elementary charge, e = 1.60 x 10 -19 C the Planck constant, h = 6.63 x 10 -34 J s unified atomic mass constant, u = 1.66 x 10 -27 kg rest mass of electron, me = 9.11 x 10 -31 kg rest mass of proton, mp = 1.67 x 10 -27 kg molar gas constant, R = 8.31 J K -1 mol-1 the Avogadro constant, NA = 6.02 x 10 23 mol-1 the Boltzmann constant, k = 1.38 x 10 -23 J K-1 gravitational constant, G = 6.67 x 10 -11 N m2 kg-2 acceleration of free fall, g = 9.81 m s -2

3 1 One form of Bernoulli’s principle for incompressi ble fluid flows states that throughout the flow, a certain quantity X remains constant. In the following expressions, m is mass, v is velocity, P is pressure, and ρ is density. Which of the expressions could possibly be correct? A B C D 2 Trucks P, Q, and R are at rest side by side. They begin accelerating at the same time. The graph of their acceleration over time is shown below. At time 2t1, which truck(s) will have covered the largest distance? A Truck P B Truck Q C Truck R D Trucks P and Q 3 A hunter aligns his rifle sight with a target. At a signal, the target falls, and the hunter fires at the same time. The bullet takes 0.8 s from the time of the signal to hit the target.  21 2Xm v p  21 2 pXm v  21 2Xv p  21 2 pXv

4 What is the initial speed of the bullet? A 12.5 m s –2 B 25.4 m s –2 C 28.0 m s –2 D 29.9 m s –2 4 Which of the following statements is true? A An object can only be in equilibrium if both its velocity and acceleration are zero. B An object at rest with average acceleration a always travels a distance of ½at2 in time t. C An object can be moving with constant speed but with non-zero acceleration. D In projectile motion, an object is at rest at the peak of its trajectory because its resultant acceleration is zero. 5 A projectile of mass m is fired from the ground with a velocity v at angle of 45 o from the horizontal. Neglecting air resistance, what is the direction and magnitude of the change in momentum of the projectile from the instant after it is fired to the instant just before it reaches the ground again? direction magnitude A − zero B → mv C → 2 mv D ↓ 2 mv 6 A box of mass 8.0 kg rests on a horizontal, rough surface. A string attached to the box passes over a smooth pulley and supports a 2.0 kg mass at its other end. When the box begins to move, a frictional force of 6.0 N acts on it. What is the acceleration of the box? A 1.4 m s-2 B 1.7 m s-2 C 2.0 m s-2 D 2.5 m s-2

5 7 A cyclist is moving with constant velocity as shown in the following figure. The rear wheel of the bicycle is powered by cyclist through a chain. The number of torque on the rear wheel The direction of the frictional force on the rear wheel by the ground Resultant torque on the rear wheel A 1 left clockwise B 2 right zero C 2 left zero D 1 right anticlockwise 8 A uniform beam is mounted horizontally by a hinge on the wall and a rope at the other end. The weight of the beam is 120 N and the force of the rope is 120 N at an angle 30 o as shown. Which of the followings gives the correct values of the reaction R on the beam by the hinge and the angle  between R and the wall? R/N  A 60 0 o B 104 90 o C 120 60 o D 164 30 o 30 o 120 N 120 N

6 9 Fig. 9 shows a diving-board held in position by two supports. A diver of weight W is hanging stationary at the end of the board with his body displaces water of weight 0.30 W. Point G is the centre of gravity of the diving board of weight 1.4 W. Which of the followings is the correct value of the vertical force acting on the bottom support by the dive board? A 2.1 W B 4.2 W C 5.4 W D 6.3 W 10 A body of mass 2.0 kg falls with a terminal velocity of 20 m s -1. Which of the following gives the correct values of the rates of work done by the weight and air resistance, and the rate of change in total energy (kinetic energy + gravitational potential energy) of the body? (take g = 10 m s-2) Rate of work done by weight / W Rate of work done by air resistance / W Rate of total energy change of body / W A +400 -400 0 B -400 +400 0 C +400 -400 -400 D zero -400 -400 L 4L G L Fig. 9

7 11 The diameter of the Singapore flyer is D and the maximum mass of each capsule and passengers is in average M. One day the flyer is operating with an average linear speed v with maximum passengers in all the N capsules. Ignore all frictional forces, the total work done in moving the whole flyer one full round with constant angular velocity is A 0 B 1 2 NMgD C 21 2NMgD NMv D 212 2MgD NMv 12 A steel ball is placed at the top of a smooth and frictionless ramp and released. The ramp is curved in a circular arc from X to Y. The acceleration of the ball at position Q is best represented by the vector A ← B → C ↓ D ↑ 13 A stone with mass m is attached to light rod. The stone is rotated in a vertical circle of radius r with a constant angular speed ω as shown. The acceleration of free fall is g. What is the difference between the maximum and minimum magnitude of the tension in the light rod during one revolution of the stone? A zero B 2mg C mrω2 D 2mrω2 X Y Q

8 14 Fig. 14 shows the variation of the resultant gravitational potential of two isolated planets X and Y with the distance r from planet A. A rocket of mass m is launched from the surface of planet X to the surface of planet Y, Assume that the fuel of the rocket is completely consumed in a negligible distance compared to the distance between the two planets. Which of the following statement is correct? A In order to reach planet Y, the minimum initial kinetic energy of the rocket is given by m(Φ 1 – Φ3). B The minimum kinetic energy of the rocket when arriving planet Y is m(