This document contains a physics module with 6 questions and diagrams about forces, energy, springs, and Hooke's law. 1. The first question discusses the forces acting on a bicycle and calculates the resultant force when an additional force is applied. 2. The second question is about a crane lifting a load and calculates the gravitational potential energy and power output. 3. The third question compares the masses and difficulty of moving two punching bags and discusses the related physics concept. 4. The fourth question draws force diagrams for pulling and pushing a trolley and calculates the vertical and horizontal force components. 5. The fifth question defines spring constant, calculates the elongation of a spring under a load

1. JABATAN PELAJARAN TERENGGANU
BIMBINGAN EMaS TAHUN 2007
PHYSICS
Module 2
Panels:
Ahmad bin Ismail
Noormi bin Ramli
Mohd Zamry bin Abdullah
Mamat bin Sulong
Zainal bin Yono

2. 1 Figure 1.1 shows some of the forces acting on a bicycle a mass of 500 kg while it cycling at a constant
velocity. Force exert by the cyclist ,P is 20 N.
Q
R P
S
FIGURE 1.1
(a) (i) Name of the force R, S and Q acted to the bicycle
S………………………………………………………………
R……………………………………………………………
Q………………………………………………………………
(ii) What is the value of the force R?
……………………………………………………………………………………..
(b) The force of the bicycle is increased to 30 N.
(i) Calculate the resultant force of the bicycle at this instant
(ii) State the movement of the bicycle.
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3. 2 Figure 2.1 shows a crane lifting a load
counterbalance
(a) What is the purpose of the counterbalance?
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(b) The crane is lifting a load of 60,000 N .
(i) The crane lifted the load trough vertical distance 15.0 m. Calculate the gravitational
potential energy gained by the load.
(ii) The load is lifted for 100 s. Calculate the power output of the crane in lifting of the
load
(c) The Power input of the crane is 72 kW, calculate the efficiency of the crane.
3 Figure 3.1 shows a boy pushed two punching bag a of mass 20 kg and B of mass 50 kg
Punching bag A
Punching bag B
FIGURE 3.1
(a) What meant of mass
…………………………………………………………………………………………..……………………………
(b) Compare the mass of the punching bag A and B
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4. (c) Compare the difficulties to moved and or stop of the two punching bags.
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(d) Name the physics concept represented by the difficulties to move or stop the punching bags.
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(e) Using your answer in (b) and (c) , state that a factor influenced to the concept. .
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(f) Explain one application of the physics concept stated in (e).
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4 Figure 4.1 show a man pull a trolley on the soft ground. Figure 4.2 show the man push the trolley at the
same placed. The force acted to trolley is 40 N. The trolley has mass 20 kg.
DIAGRAM 4.1 DIAGRAM 4.2
(a) At the diagram 4.1 and 4.2 , mark force acted to trolley.
(b) What is the weight of the trolley
(c) In the space below draw the components of force 40 N for diagram 4.1 and 4.2
(d) (i) Determine the values of the vertical component in each diagram
Diagram 4.1 :
………………………………………………………………………………………
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5. Diagram 4.2 :
………………………………………………………………………
(ii) Calculate the force acts to the ground for each diagram.
Diagram 4.1:
Diagram 4.2 :
(e) Based on your answer (d)(ii), which is easier to moved the trolley on the soft ground ?
Give one reason for your answer.
………………………………………………………………………………………………………..
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(f) If the resistance of the ground is 2 N, what is the resultant force of horizontal components
5 (a) Figure5.1 shows a steel spring with a spring constant of 20 N m-1.
DIAGRAM 5.1
(i) What is meant by the term spring constant?
(ii) Name two factors affecting the spring constant.
(iii) Calculate the elongation when a load of 15N is hung from the spring.
]
(b) A mother finds it easier to put her baby to sleep by using a spring cradle, shown in Figure 5.2
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6. DIAGRAM 5.2
A spring of either high or low spring constant may be used to make a spring
cradle.
(i) Which spring constant is more suitable for a baby’ spring cradle?
Explain your choice.
(ii) Your shop has three spring designs X, Y and Z to be used for making
cradles as shown in Figure 11.3. All springs used in designs X, Y and Z are similar
Design X Design Y Design Z
Choose and state the spring design most suitable for a baby and explain why that is that is the most
suitable design.
(iii) Explain why the other two designs are not suitable.
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7. 6 A student carries an experiment to investigate the relationship between the force ,F and extension of a
spring, x. The result of the experiment is shown in the graph of x against Fas shown in Diagram 6.1
(a) Based on the graph in Diagram 6.1 .determine the value of F when x = 2 cm.
Show on the graph ,how you determine the value of F
(b) Hooke’s Law state that the extension of a spring is directly proportional to the applied force
provided the elastic limit is not exceed
Based on the statement above , determine the range of the force that obeys the Hooke’s Law.
Show on your graph how you determine the range of the force.
(c) The relationship between the force, F and the extension, x of the spring stated as equation
below
F = kx , where k is spring contant
(i) Determine the gradient of the graph for the range as your answer (b)
(ii) Hence, determine the spring constant.
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(d) Calculate the gradient ,m when F = 5.5 N
(e) State one precaution that should be take to improve the results of this experiment.
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8. x/cm Graph extension, x againts Force,F
10
9
8
7
6
5
4
3
2
1
F/N
0 1 2 3 4 5 6 7 8
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