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Physics Form 4 Chapter 2 Force and Motion I

SPM Tips Checkpoint 2.4
To remember Newton’s First Law of Motion Q1 Figure 2.53 shows two similar tins P and Q each
when F = 0 (No resultant force) tied to a long rope.

At rest – Always stays Rope
at rest.
Sand

P Q
Figure 2.49
Push
In motion – Figure 2.53
Always moves
Chapter
• at a constant speed,
2 • in a straight line. When both the tins are pushed with the same
force,
(a) which tin is easier to be pushed?
(b) which tin is easier to be stopped?
(c) Explain your answer in (a) and (b).
Figure 2.50
Q2 Explain why
SPM Highlights (a) a loaded lorry takes a longer time to stop.
(b) a train requires a long stopping distance.
Figure 2.51 shows an (c) an oil drill platform is made of steel tubes
elephant and a tiger. that attach huge floats to the seabed.
Why is the inertia of the
elephant bigger than Q3 Figure 2.54 shows a moving toy car with a pencil
that of the tiger? box placed on top of it. It is moving towards a
A The size of the Figure 2.51 stationary obstacle.
elephant is bigger than the tiger.
B The mass of the elephant is bigger than the tiger.
C The elephant is taller than the tiger. Toy car
D The elephant is longer than the tiger. Pencil box Nail

Answer: B
Obstacle
SPM Highlights Figure 2.54

Figure 2.52 shows 2 (a) State what will happen when the car hits the
packets of the same size obstacle.
in space. One packet has (b) Explain your answer in (a)
a small mass and another (c) Compare with the effect observed if the car
big mass. How can the is moving at a higher velocity.
astronaut differentiate
between the two packets
when both are under the
condition without gravity? Figure 2.52
Answer:
Inertia depends on mass and not weight. Hence,
the packet with bigger mass is more difficult to be
moved from its initial state of rest.

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