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JPN Pahang
Teacher’s Guide
Physics Module Form 4
Chapter 4: Heat
CHAPTER 4: HEAT
4.1 : UNDERSTANDING THERMAL EQUILIBRIUM
By the end of this subtopic, you will be able to

Explain thermal equilibrium

Explain how a liquid-in glass thermometer works
Thermal equilibrium:
Keseimbangan terma
________ rate of energy transfer
A
Hot
object
B
Equivalent to
Cold
object
___________ rate of energy transfer
1.
Equivalent to
No net heat transfer
The net heat will flow from A to B until the temperature of A is the (same, zero) as the
temperature of B. In this situation, the two bodies are said to have reached thermal
equilibrium.
2.
When thermal equilibrium is reached, the net rate of heat flow between the two bodies is
(zero, equal)
3.
There is no net flow of heat between two objects that are in thermal equilibrium. Two
objects in thermal equilibrium have the ____________ temperature.
4.
The liquid used in glass thermometer should
(a)
(b)
(c)
5.
List the characteristic of mercury
(a) __________ liquid
(b) ___________ to the glass
(c) _____________ when heated
(d) Freezing point _______
(e) Boiling point _______
JPN Pahang
Teacher’s Guide
Physics Module Form 4
Chapter 4: Heat
6.
(Heat, Temperature) is a form of energy. It flows from a hot body to a cold body.
7.
The SI unit for (heat, temperature) is Joule, J.
8.
( Heat , Temperature ) is the degree of hotness of a body
9.
The SI unit for (heat, temperature) is Kelvin, K.
10.
___________ fixed point (l 0 )/ ice point
11.
____________ fixed point( l 100)/steam point: the temperature of steam from water that is
: the temperature of pure melting ice/00C
boiling under standard atmospheric pressure /1000C
Temperature, θ =
l0
l100
lθ
lθ - l0
x 1000C
l100 - l0
: length of mercury at ice point
: length of mercury at steam point
: length of mercury at θ point
Exercise 4.1
Section A: Choose the best answer
1.
The figure shows two metal blocks.
Which the following statement is false?
A.
B.
C.
D.
2.
B. It warms the water of the tea
C. It turns into heat energy and
disappears.
3.
Which of the following temperature
corresponds to zero on the Kelvin
scale?
A. 2730 C
B. 00C
C. -2730 C
D. 1000 C
4.
How can the sensitivity of a liquid- in –
glass thermometer be increased?
A. Using a liquid which is a better
conductor of heat
P and Q are in thermal contact
P and Q are in thermal equilibrium
Energy is transferred from P to Q
Energy is transferred from Q to P
When does the energy go when a cup of
hot tea cools?
A. It warms the surroundings
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Teacher’s Guide
B. Using a capillary tube with a
narrower bore.
C. Using a longer capillary tube
D. Using a thinner-walked bulb
5.
Which instrument is most suitable for
measuring
a
rapidly
changing
temperature?
A. Alcohol-in –glass thermometer
B. Thermocouple
C. Mercury-in-glass thermometer
D. Platinum resistance thermometer
Physics Module Form 4
Chapter 4: Heat
6.
When shaking hands with Anwar,
Kent Hui noticed that Anwar’s hand
was cold. However, Anwar felt that
Kent Hui hand was warm. Why did
Anwar and Kent Hui not feel the same
sensation?
A. Both hands in contact are in thermal
equilibrium.
B. Heat is flowing from Kent Hui’s
hand to Anawr’s hand
C. Heat is following from Anwar’s
hand to Kent Hui hand.
Section B: Answer all the questions by showing the calculation
1.
The length of the mercury column at the ice point and steam point are 5.0 cm and 40.0cm
respectively. When the thermometer is immersed in the liquid P, the length of the mercury
column is 23.0 cm. What is the temperature of the liquid P?
2.
The length of the mercury column at the steam point and ice point and are 65.0 cm and 5.0cm
respectively. When the thermometer is immersed in the liquid Q, the length of the mercury
column is 27.0 cm. What is the temperature of the liquid Q?
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Teacher’s Guide
3.
Physics Module Form 4
Chapter 4: Heat
The distance between 00C and 1000C is 28.0 cm. When the thermometer is put into a beaker
of water, the length of mercury column is 24.5cm above the lower fixed point. What is the
temperature of the water?
4.
The distance between 00C and 1000C is 25 cm. When the thermometer is put into a beaker
of water, the length of mercury column is 16cm above the lower fixed point. What is the
temperature of the water? What is the length of mercury column from the bulb at
temperatures i) 300C
JPN Pahang
Teacher’s Guide
Physics Module Form 4
Chapter 4: Heat
SECTION C: Structured Questions
1.
Luqman uses an aluminium can, a drinking straw and some plasticine to make a simple
thermometer as shown in figure below. He pours a liquid with linear expansion into the
can.
(a) Suggest a kind of liquid that expands linearly. (1m)
…………………………………………………………………………………………….
(b) He chooses two fixed points of Celsius scale to calibrate his thermometer. State them (2m)
………………………………………………………………………………………………
………………………………………………………………………………………………
(c) If the measurement length of the liquid inside the straw at the temperature of the lower
fixed point and the upper fixed point are 5cm and 16 cm respectively, find the length of the
liquid at 82.50C.
(d) Why should he use a drinking straw of small diameter?
………………………………………………………………………………………………
(e) What kind of action should he take if he wants to increase the sensitivity of his
thermometer?
………………………………………………………………………………………………
………………………………………………………………………………………………
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Teacher’s Guide
2.
Physics Module Form 4
Chapter 4: Heat
What do you mean by heat and temperature?
……………………………………………………………………………………………....
………………………………………………………………………………………………
………………………………………………………………………………………………
4.2
: UNDERSTANDING SPECIFIC HEAT CAPACITY
By the end of this subtopic, you will be able to
1.

Define specific heat capacity

State that c = Q/MCθ

Determine the specific heat capacity of a liquid

Determine the specific heat capacity of a solid

Describe applications of specific heat capacity

Solve problems involving specific heat capacity
Heat capacity
Muatan haba
Specific heat capacity
Muatan haba tentu
The ____________ of a body is the ______________ that must be supplied to the body to
increase its temperature by _________.
2.
3.
The heat capacity of an object depends on the
(a)
……………………………………………………………………………………….
(b)
……………………………………………………………………………………….
(c)
………………………………………………………………………………………
The ____________ of a substance is the amount of heat that must be supplied to increase
the temperature by 1 0C for a mass of 1 kg of the substance. Unit ________
Specific heat capacity, c =
Q__
m∆θ
4.
The heat energy absorbed or given out by an object is given by Q = _________
5.
High specific heat capacity absorb a large amount of heat with only a ________
temperature increase such as plastics.
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Teacher’s Guide
6.
Physics Module Form 4
Chapter 4: Heat
Conversion of energy
Heater
Electrical energy
Power = P
_________
energy
__________energ
y
Object falls from
A high position
Moving object stopped
due to friction
Heat energy
_________
Heat energy
___________
Heat energy
__________
Power = P
7.
Applications of Specific Heat Capacity
_____________
increase in
temperature
Small value of c
_________
Increase in
temperature
Two object of
equal mass
Big value of c
Equal rate of
heat supplied
Explain the meaning of above application of specific heat capacity:
(a)
(i)
Water as a coolant in a car engine
__________ is a good example of substance with a high specific capacity. It is used
as a ___________ to prevent overheating of the engine .Therefore, water acts as a
____________ as it can absorb a great amount of heat before it boils.
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Teacher’s Guide
(b)
Physics Module Form 4
Chapter 4: Heat
Household apparatus and utensils
………………………………………………………………………………………...
………………………………………………………………………………………...
………………………………………………………………………………………...
………………………………………………………………………………………...
(c)
Sea breeze
………………………………………………
………………………………………………
………………………………………………
………………………………………………
………………………………………………
………………………………………………
………………………………………………
(d)
Land breeze
………………………………………………
………………………………………………
………………………………………………
………………………………………………
………………………………………………
………………………………………………
JPN Pahang
Teacher’s Guide
Physics Module Form 4
Chapter 4: Heat
Exercise 4.2
SECTION A : Choose the best answer
1. The change in the temperature of an
object does not depend on
A. the mass of the object
B. the type of substance the object is
made of
C. the shape of the object
D. the quantity of heat received
2. Which of the following defines the
specific heat capacity of a substance
correctly?
A. The amount of heat energy required
to raise the temperature of 1kg of the
substance
B. The amount of heat energy required
to raise 1kg of the substance by 10C.
C. The amount of heat energy required
to change 1kg of the substance from
the solid state to the liquid state.
3. Heat energy is supplied at the same rate
to 250g of water and 250g of ethanol. The
temperature of the ethanol rises faster.
This is because the ethanol..
A. is denser than water
B. is less dense than water
C. has a larger specific heat capacity
than water
D. has a smaller specific heat capacity
than water
4. In the experiment to determine the
specific heat capacity of a metal block,
some oil is poured into the hole
containing thermometer. Why is this
done?
A. To ensure a better conduction of heat
B. To reduce the consumption of
electrical energy
C. To ensure the thermometer is in an
upright position.
D. To reduce the friction between the
thermometer and the wall of the
block.
JPN Pahang
Teacher’s Guide
Physics Module Form 4
Chapter 4: Heat
SECTION B: Answer all questions by showing the calculation
1.
How much heat energy is required to raise the temperature of a 4kg iron bar from 320C to
520C? (Specific heat capacity of iron = 452 Jkg-1 0C-1).
2.
Calculate the amount of heat required to raise the temperature of 0.8 kg of copper from
350C to 600C. (Specific heat capacity of copper = 400 J kg-1 C-1).
3.
Calculate the amount of heat required to raise the temperature of 2.5 kg of water from 320C
to 820C. (Specific heat capacity of water = 4200 J kg-1 C-1).
4.
750g block of an aluminium at 1200C is cooled until 450C. Find the amount of heat is
released. . (Specific heat capacity of aluminium = 900 J kg-1 C-1).
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Teacher’s Guide
5.
Physics Module Form 4
Chapter 4: Heat
0.2 kg of water at 700C is mixed with 0.6 kg of water at 300C. Assuming that no heat is
lost, find the final temperature of the mixture. (Specific heat capacity of water = 4200 J kg1
C-1)
SECTION C: Structured questions
1.
In figure below, block A of mass 5kg at temperature 1000C is in contact with another block
B of mass 2.25kg at temperature 200C.
5kg
2.25kg
A
B
1000C
200C
Assume that there is no energy loss to the surroundings.
(a) Find the final temperature of A and B if they are in thermal equilibrium. Given the
specific heat capacity of A and B are 900 Jkg-1 C-1 and 400 Jkg-1 C-1 respectively.
JPN Pahang
Teacher’s Guide
Physics Module Form 4
Chapter 4: Heat
(b) Find the energy given by A during the process.
(c) Suggest one method to reduce the energy loss to the surroundings.
…………………………………………………………………………………………..
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