2024 NYJC H1 PHY 8867 P1 Answers

NYJC 2024 8867/01/J2Prelim/24 [Turn over NANYANG JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 1 CANDIDATE NAME CLASS TUTOR’S NAME CENTRE NUMBER S INDEX NUMBER PHYSICS 8867/01 Paper 1 Multiple Choice 17 September 2024 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, class, Centre number and index number in the spaces at the top of this page. There are thirty 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. The use of an approved scientific calculator is expected, where appropriate. This document consists of 14 printed pages.

2 NYJC 2024 8867/01/J2Prelim/24 Data speed of light in free space c = 3.00 × 108 m s−1 elementary charge e = 1.60 × 10−19 C 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 the Avogadro constant NA = 6.02 × 1023 mol−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  2 2 2v u as  resistors in series 1 2 . . .R R R   resistors in parallel 1 21/ 1/ 1/ . . .R R R  

3 NYJC 2024 8867/01/J2Prelim/24 [Turn over 1 The base units of the SI system include those of The base units of the SI system include those of mass, kg; length, m; time, s; electric current, A. Which base units would be needed to express the SI unit of potential difference (the volt)? A m and A only. B s and A only. C m, s and A only. D kg, m, s and A. 2 A car travelling at a speed of 15.0 m s1 can be brought to rest in 1.20 s when a uniform braking force is applied. The reaction time of the driver is 0.100 s. What is the minimum distance at which the driver must notice a stationary object in order to avoid hitting it? A 1.50 m B 7.50 m C 9.00 m D 10.5 m 3 Which pair contains one vector and one scalar quantity? A displacement and acceleration B force and kinetic energy C momentum and velocity D power and speed 4 An object has an initial velocity u. It is subjected to a constant force that is not in the same direction as u, resulting in acceleration a. The vector diagram below is drawn to determine the object’s final velocity v after time t. What is the length of the vector X in the diagram? A v  u B v  u C at D u  at (D)   -2 2 2 2 15.00 15.0 m s 1.20 15.00 15.0 9.00 m 1.20 1.20 2 2 v u at a a sv u as s                     Thinking distance = 15.0  0.100 m = 1.50 m Total dist = 9.00 + 1.50 = 10.50 m (B) u X v

4 NYJC 2024 8867/01/J2Prelim/24 5 Ball P is projected upwards from the bottom of a smooth inclined plane with an initial speed that is just sufficient for it to reach the top of the plane. At the same time that Ball P is projected, Ball Q is projected downwards from the top of the plane with the same initial speed as Ball P. What is the ratio of the distance travelled by Ball 2 to the distance travelled by Ball 1 when they collide? A 0.78 B 1.0 C 1.3 D 3.0 Ball P Ball Q (C) From 1 21s ut at 2  and 2 21s ut at 2  , where a = g sin   1 2 2s s ut  (1) From v2 = u2  2as,  1 2 2us s 2 a  (2) From (1) & (2), 2 4 2uut 2 a ut a     9 4 8 1 37 84 2 2 21 1 u1 u aut ats 2 a2 .1 1 us ut at u a2 2 a               (C) The vectors all represent the same quantity for the equation to be homogeneous and hence correct. We need to find the change in velocity that that acceleration causes in time t. Hence , we add this change to the initial velocity. Since v = u + at, and the change v = v  u = X = at.

5 NYJC 2024 8867/01/J2Prelim/24 [Turn over 6 The sketch graph below describes the motion of a ball rebounding from a horizontal surface after being released from a point above the surface. The quantity represented on the y-axis is the ball’s A velocity. B kinetic energy. C acceleration. D displacement. 7 The rate of change of momentum experienced by a free -falling ball when it hits the ground is equal to A its weight. B the net force acting on it. C the force exerted on it by the ground. D the impuse on the ball due to the ground. 8 A stone of mass m is projected with velocity v from a point P as shown below. Neglecting the effects of air resistance, what is the magnitude of the change in momentum between leaving P and arriving at Q? A zero B mv C 2mv D 2mv (B) By Newton’s second law. y time (D) Gradient of s-t graph gives velocity (C) f i f i( ) ( ( )) 2 cos 45 2 m v m v v m v v mv mv           P Q v 45°

6 NYJC 2024 8867/01/J2Prelim/24 9 Two blocks, X and Y, of masses m and 2m respectively, are accelerated along a smooth horizontal surface by a force F as shown in the diagram below. What is the magnitude of the force exerted by block Y on block X during the acceleration? A 6 F B 3 F C 2 3 F D 5 6 F 10 The diagram shows a ball of weight W hanging in equilibrium from a string. The string is at an angle  to the vertical. The tension in the string is T. The ball is held away from the wall by a horizontal force P from the metal rod. Which relationship between the magnitudes of T, P and W is correct? A cos and sinP T W T    B T P W  C 2 2 2T P W  D tan and cosW P W T    2 2 2 (C) cos and sin (by Pythagoras theorem) T W T P W P T       X Y F (C) Acceleration of system 3 F m 22 3 3 YX XY F FF F m m       

7 NYJC 2024 8867/01/J2Prelim/24 [Turn over 11 A uniform bar of length L and weight W rests horizontally on two supports X and Y. Support X exerts a vertical force RX at a distance of L 6 from one end of the bar. Support Y exerts a vertical force RY at the other end of the bar. The bar is in equilibrium. What is the ratio X Y R R ? A 3 2 B 2 3 C 3 5 D 2 5 12 A type of firework is made by connecting two rockets, facing opposite directions, to a rod as shown. The rod is attached to a frictionless pivot so that the firework can rotate in a vertical plane. The firework has weight W. The pivot exerts a force R on the rod that is equal and opposite to W. Each rocket exerts a force of magnitude F on the rod at a perpendicular distance d from the pivot. The forces exerted by the rockets are always in oppsite directions. (A) Taking moments about C.G. 3 2 3 2 X Y X Y L LR R R R           

8 NYJC 2024 8867/01/J2Prelim/24 Air resistance is negligible. Which statement is correct? A The firework is in equilibrium because the resultant force acting on it is zero. B The firework is in equilibrium because the resultant torque acting on it is zero. C The firework is not in equilibrium because the resultant force acting on it is not zero. D The firework is not in equilibrium because the resultant torque acting on it is not zero. 13 A square board, of side length x, hangs freely from a nail P, as shown. The board has uniform thickness and is made from material of uniform density.