TMJC_2023_H2 Physics_P3_MS

1 Tampines Meridian Junior College 2023 JC2 Preliminary Examination H2 Physics Tampines Meridian Junior College 2023 JC2 H2 Physics Preliminary Examination Paper 3 Suggested Solution 1 (a) (i) Elastic collision (as the total kinetic energy of the system (car and wall) is conserved before and after collision) [B1] (ii) Considering the toy car and the wall as one system, The total momentum is conserved as there is no external resultant force acting on this system. There is a corresponding change of momentum to the fixed wall. Or Considering the toy car as the system only, The momentum is not conserved as there is an external resultant force acting on the toy car by the wall. [B1] [B1] [B1] [B1] (b) (i) -1 area under - graph 1 (0.18)( 15)2 1.35 kg m s p Ft∆= = − =− -1 () () 1.35 2 1.35 2 0.675 ms kg fi fi i ppp mv v mv v mv p mv ∆= − = − = −− −= − = = = [C1] [A1] (ii) max 11 ( 15) 7.5 N N 22 or 1.35 (0.18) 7.5 average average average average FF pF t F F = = −= − ∆= −= =− -2 7.5 0.65 11.5 m s average average average average F ma a a = −= =− [C1] [A1]

2 Tampines Meridian Junior College 2023 JC2 Preliminary Examination H2 Physics Or -1 -2 0.675 0.65 1.04 m s 1.04 1.04 0.18 11.6 m s ii i fi p mv v vva t = = = −= −−= =− [C1] [A1] (iii) [B1] shape with the time increased and magnitude of max force decreased. force / N time / s 0 0.18 −15

3 Tampines Meridian Junior College 2023 JC2 Preliminary Examination H2 Physics 2 (a) A field of force is a region of space in which a body experiences a force without physical contact with another body. [The field is produced by the presence of another body (or bodies)]. [B1] (b) State one similarity and one difference between gravitational field and electric field. Similarity [B1]: o The field strength due to a point charge/mass follows an inverse square law with distance from the charge/mass. o The potential due to a point charge/mass varies inversely with distance from the charge/mass. o (Both G-fields and E-fields can be represented by field lines) In notes, we accept for students who memorised. Difference [B1]: o Gravitational fields are always attractive, whereas electric fields can be attractive or repulsive. o Gravitational potential is always negative, whereas electric potential can be positive or negative. o Source of gravitational field is a mass while source of electric field is a charge. (c) (i) At point P, it is a gravitational neutral point where net gravitational field strength g is zero. [B1] It is closer to the moon since the mass of the moon is smaller than the mas