ACJC 2025 J2 H2 Physics Prelim P2 Guide

Anglo-Chinese Junior College 2025 J2 Preliminary Exam Paper 2 Guide H2 (9749) Physics JC2 2025 Page 1 of 10 Qn Suggested Solutions 1(a)(i) ( )( )0.140 4.0 5.4 p mv mu = − = − − 1.3 N sp =− (ii) 1.3 32.5 N0.04 pF t = = = ( )32.5 0.14 9.81 34 N F N mg N N =− =− = By Newton’s 3rd law, magnitude of the force exerted by the ball on the bar = magnitude of the force by the bar on the ball, N (b) Taking moments about B, ( ) ( )( ) ( )34 75 0.450 9.81 25 20 AF+= 133 NAF =

Anglo-Chinese Junior College 2025 J2 Preliminary Exam Paper 2 Guide H2 (9749) Physics JC2 2025 Page 2 of 10 Qn Suggested Solutions 2(a)(i) 2 y y y 1 2s u t a t=+ 21220sin(30 )(16.8) (9.81)(16.8)2 =+x 3230 m=x (ii) 1 xx 220cos(30 ) 190.5 m svu −= = = y y yv u a t=+ 1 y 220sin(30 ) 9.81 (16.8) 274.8 m sv −= + = 22 xyv v v=+ 22190.5 274.8=+v 1334 m sv −= OR ( ) 2 k 1initial 220 2Em= ( )( ) Ploss in gravitational 9.81 3232 E mgh m = = final kinetic energy = loss in gravitational potential energy + initial kinetic energy ( )( ) ( ) 2211 9.81 3232 22022mv m m=+ 1334 m sv −= (iii) (b) vx / t / s vx / 1m s− t/s 191 16.8 S vx / 1m s− t / s 191 16.8 R S

Anglo-Chinese Junior College 2025 J2 Preliminary Exam Paper 2 Guide H2 (9749) Physics JC2 2025 Page 3 of 10 Qn Suggested Solutions 3(a) (b)(i) Although the magnitude of the velocity is constant, its velocity is changing as the direction of its velocity is always changing. According to Newton’s Second Law, the astronaut must experience rate of change of momentum / an acceleration and hence a resultant force. Both the acceleration and force act towards the centre. (ii) 2 2 9.81 100 10199.81 vg r r == == 1020rm=

Anglo-Chinese Junior College 2025 J2 Preliminary Exam Paper 2 Guide H2 (9749) Physics JC2 2025 Page 4 of 10 Qn Suggested Solutions 4(a) A polarised wave has its vibrations/oscillations occur in a single direction in a plane / restricted to one plane (axis) and perpendicular to the direction of transfe