This document contains a summary of a physics module covering topics like motion, forces, energy, and momentum. It includes 6 questions with diagrams and graphs related to: 1) The motion of a car braking to avoid a road block. 2) Conservation of momentum applied to a man jumping off a moving boat. 3) Forces and air resistance affecting the motion of falling objects. 4) Equilibrium of forces on hanging mirrors. 5) Changes in energy and shape during collisions between plasticine balls and surfaces. 6) The relationship between force and acceleration on an object moving on a rough surface, as shown by a graph.

1. JABATAN PELAJARAN TERENGGANU
BIMBINGAN EMaS TAHUN 2007
PHYSICS
Module 3
Panels:
Ahmad bin Ismail
Noormi bin Ramli
Mohd Zamry bin Abdullah
Mamat bin Sulong
Zainal bin Yono

2. 1 While traveling along the road at velocity 20 m s -1, a car driver suddenly sees the road
ahead blocked at the distance 62 m from the car. He applies the brakes as fast as he
can. Once the brakes are applied, the car still moves fastly. He applies the brakes
again more strongly until it stops before the road block. Graph in Figure 1 shows the
motion of the car.
FIGURE 1
(a) What is meant by velocity?
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(b) How long the time taken by the driver during he starts see the road block until the
car stopped.
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(c) Calculate the distance between the car and the road block when the car stop.
(d) Based on the graph velocity- time above , sketch the graph acceleration- time.
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3. 2 Figure 2 shows a man standing on a stationary boat. He then jumps out of the boat onto
the jetty . The boat moves away from the jetty as he jumps.
Jetty
FIGURE 2
(a) State the physics principle that is involved in the movement of the boat as the man
jumps onto the jetty.
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(b) Explain why the boat moves away from the jetty when the man jumps.
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(c) The mass of the man is 50 kg and he jumps at a velocity of 2 m s-1 . The mass of
the boat is 20 kg. Calculate the velocity of the boat as the man jumps.
(d) Name one application of the physics principle stated in (a) in an exploration of outer
space.
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4. 3 Figure (a) shows a feather and a water droplet falling from the same height. The mass
of the feather and the water droplet is the same and both are dropped simultaneously at
time t = 0 s.
The graph in Figure (b) shows the motion of the feather and the water droplet from t =
0 s.
(a) Name one force acting on the feather and the water droplet.
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(a) Using Figure (a), compare the surface area of the feather and the water droplet.
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(c) Using the graph in Figure (b), compare the changes in the velocity of the feather
and the water droplet.
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(d) Using the answer in (b) and (c), state the relationship between the surface area
and the final velocity.
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5. (e) The feather and the water droplet are dropped in a vacuum. Sketch a velocity-time
graph to show the motion of both objects on the figure below.
4 Figure 4.1 and Figure 4.2 shows two identical mirrors which are hung on the wall using
strngs, of the same length.
T1 T2
T2 T2
A 60 o 60 o
B
A 30 o 30 o B
D C
D C
FIGURE 4.1 FIGURE 4.2
The two mirrors are in equilibrium state. Each mirror has a mass of 2 kg. Each string
can withstand a maximum force of 15 N.
(a) What is meant by equilibrium state?
………………………………………………………………………………………………...
[1 mark]
(b) What is the weight of any one of the mirrors?
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[1 mark]
(c) In the space below, draw a diagram of triangle of forces that acts on the mirrors in
Figure 4.1 and Figure 4.2.
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6. Diagram of a triangle of forces for Figure 4.1 Diagram of a triangle of forces for Figure 4.2
(d) T1 and T 2 are the tensions of the strings that act on the mirrors in Figure 4.1 and
4.2 respectively.
(i) In the space below, draw the scale drawings of the triangles of forces to
determine the values of T1 and T2
[Use the scale 1 cm : 2 N]
T1 = …… cm
= ……. N
T2 = …… cm
= ..…… N
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7. (ii) Based on your answer in 4(d)(i), which is the most suitable method to hang the
mirror? Give one reason for your answer.
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(e) If the string in Figure 4.1 is cut, the mirror will fall down in 0.6 s. Calculate the final
velocity of the mirror before it touches the surface of the floor.
5 Figure (a) shows two identical plasticine spherical balls before being released from the
same height. Figure (b) shows the state of the plasticine balls when the hit the wood
and the sponge. It was observed that the plasticine stopped more quickly when it hit the
wood.
Figure (b)
(a) (i) What does the word momentum mean?
[1 mark]
(ii) Observe Figure (a) and Figure (b). Compare the shape of the plasticine balls,
the surface of the wood, the surface of the sponge before and when the
plasticine balls hit the surfaces.
Relate the changes in shapes of the plasticine balls and the surfaces to
deduce a relevant physics concept.
[5 marks]
(b) Explain the changes in energy that occur from the moment the plasticine ball is
released until it reaches the position in Figure (b).
[4 marks]
(c) An earth-monitoring satellite falls into the earth’s atmosphere at a high velocity and
reaches a high temperature. This is caused by the earth’s gravitational force and
air resistance.
Using the appropriate physics concepts, suggest and explain suitable designs or
ways to protect the satellite and its equipment:
(i) from extreme heat,
(ii) from breaking up on landing.
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8. 6 A graph shows an experiment results to identify the relationship between force, F and
acceleration, a for an object which moves on a rough surface runaway.
F/N
25
20
15
10
5
a/ms-2
0 1 2 3 4 5 6 7 8
(a) Based on the graph,
(i) show and determine the value of F when a = 0.0 ms -2.
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(ii) name the physical quantity which represents the value at (a) (i)
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(iii) what will happen to a when F is increased
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9. ( b) From the graph,
(i) determine the gradient
(ii) name the physical quantity that represents the value of the gradient in
(b) (i).
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(c) From the graph, identify the value of a when F=14.0 N. Show on the graph
how you determine the value.
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(d) Based on the graph, write the relationship between F and a.
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(e) State one precaution that should be taken for this experiment.
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