ED2484A_SCE551 LESSON BOOK DEVELOPMENT

FIRST EDITION MASTERING
PHYSICS: HEAT

AUTHOR & EDITOR:
NUR ARISYA FARHANA BINTI MOHD ZULKIFLI

FEB 2022

MASTERING PHYSICS: HEAT

Effective Reference, Graphical & Diagrammatic

WeRead Publications Sdn. Bhd.
No. 12, Jalan Nuri, Taman Impian,
46150 Petaling Jaya, Selangor Darul Ehsan.
Tel: 03-6743 9062 Fax: 03-6743 4062

Email: [email protected]
Website: www.wereadpublications.com

© WeRead Publications Sdn. Bhd.

First published 2022
ISBN: 978-123-456-789-7

All rights reserved.
No part of this publication may be reproduced, stored in
a retrieval system, or transmitted, in any form or by any
means, electronic, mechanical, photocopying, recording

or otherwise, without the prior permission of
WeRead Publications Sdn. Bhd.

i

Acknowledgement

Bismillahirahmannirahim.
All glory and praise to Allah S.W.T for providing me with the
courage and strength to complete this lesson book.
I would want to express my gratitude to everyone who helped me
completed this lesson book by contributing ideas and hands. On the
other side, I would want to show my heartfelt gratitude to my
lecturer, Madam Norezan, because I could not have done it without
her direction and help in developing my priceless lesson book.
Finally, I am overwhelmed by the support I have received from my
parents and classmates. Thank you so much for constantly providing
positive feedback and suggestions for making this lesson book more
entertaining.
I hope that my lesson book will benefit physics students by
assisting them in gaining a better knowledge of the topics included
in the book.

ii

Preface

This lesson book was created based on the Physics Textbook KSSM
Form 4 and the Dokumen Standard Kurikulum Pentaksiran (DSKP)
provided by the Ministry of Education, Malaysia. This book aims to
help students understand mastering Chapter 4: Heat. It is guided by
the concepts of 21st century skills and STEM teaching and learning
approach. The objective of this lesson book is to boost students'
memories in the topic with colourful graphical based on 21st century
skills needed for better understanding.

Special Features

Learning Outcome Feed your brain!

Statements that define the Additional information about
knowledge or skills that the theories, facts and
concepts.
students should have by the
end of each subtopic in this

book, as well as why that
knowledge and skill will be

helpful to them.

Exercises

Questions to test students
understanding at the end of
the chapter including all of

the subtopics.

iii

Table of Contents

Copyright i
Acknowledgement ii
Preface iii

HEAT 1-2
3-5
4.1 Thermal Equilibrium 6-8
4.2 Specific Heat Capacity 9-10
4.3 Specific Latent Heat
Exercises 11
References

iv

Chapter 4 Theme 3: Heat
Heat
4.1 Thermal Equilibrium

Heat is the flow or transfer of thermal energy from a Learning Outcome

hotter object to a cooler object At the end of this
subtopic, student should
Thermal equilibrium is reached between two objects in be able to:
• Explain with examples
thermal contact when:
• There is no net heat transfer between them thermal equilibrium in
• They have the same temperature daily life
• Calibrate a liquid-in-
glass thermometer
using two fixed-points

Temperature drops in the Temperature rises in the
hot coffee due to small heat cold metal spoon due to
transfer from the spoon. large heat transfer from
the hot coffee

Finally, both have the same
temperature at thermal
equilibrium

Two objects not in thermal equilibrium: Two objects in thermal equilibrium:
• Net heat transfer from A to B occurs • Net heat transfer between A and B = 0
• Temperature of A > temperature of B • Temperature of A = temperature of B

Feed your brain!

Thermal equilibrium is a concept found in Ralph H. Fowler's Zeroth Law
of Thermodynamics, which he named in 1935. It was dubbed the "Zeroth
Law" because three other thermodynamic laws had already been
established and named. The Zeroth Law states that two bodies are in
thermal equilibrium if they are both in thermal equilibrium with a third
body. Temperature is a property that is used to determine whether or
not a system is in thermal equilibrium.

1

Calibrating a Liquid-in-glass Thermometer using Two Fixed Points

1. Place a thermometer bulb into melting ice
until thermal equilibrium at 0°C. Mark the

ice point on the stem.

2. Place the thermometer bulb into steam until
thermal equilibrium at 100 °C. Mark the steam

point on the stem.

3. Divide the length between the two fixed points into 100 equal
divisions so that each division = 1°C. Temperature, θ can also be
calculated using the formula:

θ = − 0 or θ = x 100 °C
100 − 0 100

Feed your brain!

Calibration is the process of determining the precision and quality of measurements
taken using a piece of equipment. When employing technologies or monitoring
characteristics like temperature and humidity, there is a propensity for results and
accuracy to 'drift' with time. It is necessary to maintain the calibration of
equipment throughout its lifetime in order to have confidence in the data being
measured. This ensures that measurements are trustworthy, accurate, and
repeatable. The purpose of calibration is to reduce measurement uncertainty by
ensuring that test equipment is accurate. Calibration is the process of quantifying
and controlling mistakes or uncertainties in measuring processes to a safe level.

2

4.2 Specific Heat Capacity

Heat capacity, C of an object is the amount of heat required Learning Outcome
to increase the temperature of the object by 1°C.
At the end of this subtopic,
C = ∆ , where Q = amount of heat applied student should be able to:
∆ = temperature change • Explain heat capacity, C.
• Define specific heat
Unit of C: J℃−1.
capacity of a material, c.
Specific heat capacity, c of a substance is the amount of c =
heat required to increase the temperature by 1°C for 1 kg
mass of the substance. (∆ )

C = ∆ , where Q = amount of heat applied • Experiment to determine
m = mass (in kg) the specific heat capacity
∆ = temperature change of water and the specific
heat capacity of
Unit of C: J℃−1. aluminium.

• Solve problems involving
specific heat capacity.

• Communicate to explain
the applications of
specific heat capacity in
daily life and natural
phenomena.

Temperature rise is higher in sand than in water, ∆ > ∆ .
Heat capacity of sand is lower than that of water, > .

Temperature rise, Temperature rise,

∆ = 40 ℃ ∆ = 8 ℃
∆
Heat capacity, = Heat capacity, =
∆
32 32
= 40℃ = 0.8 ℃−1 = 8℃ = 4.0 ℃−1

150 g 150 g
of sand of water

Q = 32 J

Specific heat capacity is greater Specific heat capacity is smaller

Water takes a longer time to heat up to the same temperature as oil. Water
absorbs more heat to produce a small temperature rise. Specific heat capacity

of water is greater than oil

3

Determine the Specific Heat Capacity of a Solid and a Liquid

To determine the specific
heat capacity of a solid
(aluminium)

To determine the specific
heat capacity of a liquid
(water)

12 The heater is 3
switched off and The specific heat
The initial temperature, the final capacity, c is
1 is recorded. The temperature, 2 calculated from the
heater is turned on for is recorded. equation: mc( 2 - 1) =
time, t = 10 min. Pt, where P = power of
the heater

Example

A 440 g brass sphere is heated to 100 °C in boiling water. It is
quickly transferred to a polystyrene cup containing 200 g of water
at 28 °C. The temperature of the water rises to 40 °C at thermal
equilibrium. Calculate the specific heat capacity of brass.
[Specific heat capacity of water is 4200 J −1 ℃−1]

Solution

Heat supplied = mc∆
Heat loss by brass sphere = Heat gained by cold water

0.440 x c x (100 – 40) = 0.200 x 4200 x (40 – 28)
0.200 4200 12

c = 0.440 60 = 382 J −1 ℃−1

4

Applications of Specific Heat Capacity in Daily Life

Sea breeze

Cooking pan Handle

• Plastic
• High specific heat capacity
• Poor heat conductor

Body Base
• Steel • Copper
• Low specific heat capacity • Low specific heat capacity
• Heats up quickly • Heats up quickly

Car radiator system Coolant
• Water
Fan/Cooling Fin • High specific heat
• Painted black
• Good absorber and capacity
• Can absorb plenty of
radiator of heat
• Fan draws in air to cool heat before it boils.

water 5

4.3 Specific Latent Heat

• Matter exists in three Learning Outcome
phases, that is solid,
liquid and gas. At the end of this
subtopic, student should
• Latent heat is the heat be able to:
absorbed or released by • Explain latent heat.
a substance during a • Define specific latent
change of phase without
change in temperature heat, , = mQ, specific
latent heat of fusion,
• Specific latent heat of , specific latent
fusion, is the amount heat of evaporization,
.
of heat required to • Communicate to
change 1 kg of a explain the
substance from solid to applications of
liquid phase without specific latent heat in
change in temperature. daily life.
• Solve problems
• Specific latent heat of vaporisation, is the amount of heat involving latent heat
required to change 1 kg of a substance from liquid to gaseous
phase without change in temperature.

Specific latent heat, = Q
m

Q = heat absorbed or released,
m = mass of the substance. Unit of : J −1

Boiling is a vaporisation Bubbles form in the
process of a liquid that occurs liquid and rise the
• Quickly
• Throughout the liquid surface
• With bubbles formed
• At boiling point only Bubbles do not form in
• And needs latent heat the liquid

supplied by a heat energy 6
source

Evaporation is a vaporisation
process of a liquid that occurs
• Slowly
• Only at the liquid surface
• With no bubbles formed
• At all temperatures
• And needs latent heat

supplied by the
surroundings

Heating Curve and Cooling Curve

Heating Curve

• Latent heat is absorbed.
• Constant temperature.
• Kinetic energy of molecules

unchanged.
• Intermolecular bonds

weakened/broken

Cooling Curve

• Latent heat is released.
• Constant temperature.
• Kinetic energy of molecules

unchanged.
• Intermolecular bonds formed

back.

Liquid
+ solid

7

Applications of Specific Latent Heat in Daily Life

Cooling effect when perfume or alcohol is applied on our body

Perfume or alcohol
evaporates easily and
quickly. Latent heat

absorbed from our
body makes us feel

cool.

Cooling effect when perfume or alcohol is applied on our body If it is windy, we
feel even colder. The
Evaporation of rate of evaporation
sweat or water is increased by wind
absorbs latent heat
from our body. This or air movement.
causes a cooling

effect.

Solving Problems Involving Latent Heat

Example

A hand dryer blows out hot air to dry wet hands. The heater inside
the dryer supplies heat energy to the air at the rate of 2500 W.
in one second, 75 g of cold air at 28 °C enters the hand dryer. It
emerges as hot air. Calculate the temperature of the hot air that
emerges. [Specific heat capacity of air = 1100 J −1 ℃−1]

Solution
Heat supplied in 1 second, Q = 2500 J

mc( 2 − 1) = 2500
2500

2 − 28 = 0.075 1100
2 = 28 + 30.3
= 58.3 ℃

8

Exercises

1. Which situation is not in thermal equilibrium?

A. Ice left in water for 0 minutes
B. A spoon left in hot soup for 10 minutes
C. A spoon is put into a glass of iced tea
D. Rocks are immersed in the river for 4 hours

2. Table 1 shows the values of specific heat capacities for substances X,Y and Z.

Substance Specific heat capacity (J
− ℃− )
X
Y 3400
Z
438

860

Which pair of substances is most suitable for the
making of the base and the handle of a frying pan?

Base Handle

A. Y X
B. X Y
C. Z X
D. X Z

3. Diagram 1 shows a process in which a solid changes to a liquid.

Solid 0 °C Liquid

Diagram 1

The heat absorbed during the process is named as

A. Specific heat capacity of solid
B. Specific heat capacity of liquid
C. Specific latent heat of vaporization
D. Specific latent heat of fusion

9

Exercises
4. 9650 J of heat is used to increase the temperature of a 3.0 kg metal block.

The specific heat capacity of the metal block is 640 J −1 ℃−1. What is the
rise in temperature of the metal block?

5. 0.50 kg of water at temperature of 70 °C is poured into a glass of ice cubes
at 0 °C. What is the mass of the ice cubes that melt? [Specific latent heat of
vaporisation of ice = 3.36 x 105 J −1 ℃−1, specific heat capacity of water =
4200 J −1 ℃−1]

10

References

1. 11.2 Heat, Specific Heat, and Heat Transfer - Physics |
OpenStax. (n.d.). Openstax.org.
https://openstax.org/books/physics/pages/11-2-heat-specific-
heat-and-heat-transfer

2. Choy, C. S., Chuan, K. K., Beng, Dr. O. H., Md Mustafa, M. K. A.,
& Ragavan, R. (2019). KSSM Physics Form 4.
http://anyflip.com/txlwk/remh

3. Elert, G. (2019). Glenn Elert. The Physics Hypertextbook;
physics.info. https://physics.info/temperature/

4. Form 4 physics Chapter 4 Heat Teachers Guide - [PDF
Document]. (n.d.). Cupdf.com. Retrieved January 6, 2022, from
https://cupdf.com/document/form-4-physics-chapter-4-heat-
teachers-guide.html

5. Heat (Energy) Transfer and Thermal Equilibrium - Physics 298.
(n.d.). Www.physics.louisville.edu. Retrieved January 6, 2022,
from
https://www.physics.louisville.edu/cldavis/phys298/notes/heat
_thermeq.html

6. Ling, S. J., Moebs, W., & Sanny, J. (2016, September 15).
Temperature and Thermal Equilibrium. Opentextbc.ca;
OpenStax.
https://opentextbc.ca/universityphysicsv2openstax/chapter/t
emperature-and-thermal-equilibrium/

7. Lumen Learning. (2013). Specific Heat | Boundless Physics.
Lumenlearning.com.
https://courses.lumenlearning.com/boundless-
physics/chapter/specific-heat/

8. Specific heat, heat of fusion and vaporization example. (2016).
Specific heat, heat of fusion and vaporization example. Khan
Academy.
https://www.khanacademy.org/science/chemistry/states-of-
matter-and-intermolecular-forces/states-of-
matter/v/specific-heat-heat-of-fusion-and-vaporization

9. Specific latent heat - Temperature changes and energy - AQA
- GCSE Physics (Single Science) Revision - AQA. (n.d.). BBC
Bitesize.
https://www.bbc.co.uk/bitesize/guides/zcncjty/revision/5

10. Thermodynamics article (article). (n.d.). Khan Academy.
Retrieved January 6, 2022, from
https://www.khanacademy.org/test-prep/mcat/chemical-
processes/thermodynamics-mcat/a/thermodynamics-
article#:~:text=When%20two%20systems%20are%20in

11

MASTERING
PHYSICS: HEAT

FIRST EDITION

EVERYBODY IS A GENIUS
BUT IF YOU JUDGE A
FISH BY ITS ABILITY TO
CLIMB A TREE, IT WILL
LIVE ITS WHOLE LIFE
BELIWVING THAT IT IS
STUPID

Albert Einstein

WM: RM10.90/EM: RM11.50

ISBN: 978-123-456-789-7

WEREAD PUBLICATIONS
Website: www.wereadpublications.com
Email: [email protected]