spm physics form 4 heat
DESCRIPTION
http://study4spm.blogspot.com/TRANSCRIPT
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
86
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
1. 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) Be easily seen
(b) Expand and contract rapidly over a wide range of temperature
(c) Not stick to the glass wall of the capillary tube
5. List the characteristic of mercury
(a) Opaque liquid
(b) Does not stick to the glass
(c) Expands uniformly when heated
(d) Freezing point -390C
(e) Boiling point 3570C
Thermal equilibrium
:Keseimbangan terma
CHAPTER 4: HEAT
……………………………………………………………………………..
……………………………………………………………………………….
……………………………………………………………………………..
……………………………………………………………………………………..
…………………………………………………………………………………….
…………………………………………………………………………………….
…………………………………………………………………………………….
…………………………………………………………………………………….
…………………………………………………………………………………….
………….. rate of energy transfer
Hot
object
Cold
object
………….. rate of energy transfer
Equivalent to Equivalent to
No net heat transfer
A B
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
87
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. Lower fixed point (l 0 )/ ice point : the temperature of pure melting ice/00C
11. Upper fixed point( l 100)/steam point: the temperature of steam from water that is boiling
under standard atmospheric pressure /1000C
Exercise 4.1
Section A: Choose the best answer
1. The figure shows two metal blocks.
Which the following statement is
false?
A. P and Q are in thermal contact
B. P and Q are in thermal equilibrium
C. Energy is transferred from P to Q
D. Energy is transferred from Q to P
2. When does the energy go when a cup
of hot tea cools?
A. It warms the surroundings
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?
……………………………..…
…………………………………
l0 : length of mercury at ice point
l100 : length of mercury at steam point
lθ : length of mercury at θ point
Temperature, θ = lθ - l0
l100 - l0 x 100
0C
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
88
A. Using a liquid which is a better
conductor of heat
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
6. When shaking hands with Anwar,
Kent Hui niticed 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?
Temperature, θ = lθ – l0 x 1000C
l100 – l0
θ = 27 – 5 x 1000C
65 - 5
θ = 36.670C
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
2
3. The distance between 00C and 100
0C 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 100
0C 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 Physics Module Form 4
Student’s Copy Chapter 4: Heat
3
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?
………………………………………………………………………………………………
………………………………………………………………………………………………
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
4
2. What do you mean by heat and temperature?
……………………………………………………………………………………………....
………………………………………………………………………………………………
………………………………………………………………………………………………
: UNDERSTANDING SPECIFIC HEAT CAPACITY
By the end of this subtopic, you will be able to
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
1. The ……………….. of a body is the …………………….. that must be supplied to the
body to increase its temperature by 10C.
2. The heat capacity of an object depends on the
(a) ……………………………………………………………………………………….
(b) ……………………………………………………………………………………….
(c) ………………………………………………………………………………………
3. 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 Jkg
-1 K
-1
4. The heat energy absorbed or given out by an object is given by Q = mc∆O.
5. High specific heat capacity absorb a large amount of heat with only a
……………temperature increase such as plastics.
Heat capacity
Muatan haba
Specific heat capacity
Muatan haba tentu
Specific heat capacity , c = Q__
m∆θ
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
5
6. Conversion of energy
7. Applications of Specific Heat Capacity
Explain the meaning of above application of specific heat capacity:
(a) Water as a coolant in a car engine
(i) ....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
Electrical energy Heat energy
Pt = mcθ
Heater
Power = P
…………energy
…………..energy
…………..energy
Object falls from
A high position
Moving object stopped
due to friction
Power = P
Heat energy
mgh= mcθ
Heat energy
½ mv2= mcθ
Small value of c Big value of c Two object of
equal mass
Equal rate of
heat supplied
……….
increase in
temperature
…………….
increase in
temperature
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
6
(b) Household apparatus and utensils
………………………………………………………………………………………...
………………………………………………………………………………………...
………………………………………………………………………………………...
………………………………………………………………………………………...
(c) Sea breeze
………………………………………………
………………………………………………
………………………………………………
………………………………………………
………………………………………………
………………………………………………
………………………………………………
(d) Land breeze
………………………………………………
………………………………………………
………………………………………………
………………………………………………
………………………………………………
………………………………………………
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
7
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.
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).
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
87
2. Calculate the amount of heat required to raise the temperature of 0.8 kg of copper from
350C to 60
0C. (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 82
0C. (Specific heat capacity of water = 4200 J kg
-1 C
-1).
4. 750g block of a aluminium at 1200C is cooled until 45
0C. Find the amount of heat is
released. . (Specific heat capacity of aluminium = 900 J kg-1
C-1
).
5. 0.2 kg of water at 700C is mixed with 0.6 kg of water at 30
0C. Assuming that no heat is
lost, find the final temperature of the mixture. (Specific heat capacity of water = 4200 J
kg-1
C-1
)
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
88
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.
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.
(b) Find the energy given by A during the process.
(c) Suggest one method to reduce the energy loss to the surroundings.
…………………………………………………………………………………………..
A
B
1000C 20
0C
5kg
2.25kg
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
89
UNDERSTANDING SPECIFIC LATENT HEAT
By the of this subtopic, you will be able to
State that transfer of heat during a change of phase does not cause a change in temperature
Define specific latent heat
State that l = Q/m
Determine the specific latent heat of fusion and specific latent heat of vaporisation
Solve problem involving specific latent heat.
1. Four main changes of phase.
2. The heat absorbed or the heat released at constant temperature during a change of
phase is known as latent heat. Q= ml
3. Complete the diagrams below and summarized.
(a) Melting
Solid Solidification
Latent heat …………
Boiling
Latent heat ………….
Condensation
Latent heat …………
Liquid
Gas
Temperature
Time
………………………………………
………………………………………
………………………………………
………………………………………
………………………………………
………………………………………
……………………………………….
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
90
(b) Boiling
(c) Solidification
(d) Condensation
Temperature
Time
………………………………………
………………………………………
………………………………………
………………………………………
………………………………………
………………………………………
……………………………………….
Temperature
Time
………………………………………
………………………………………
………………………………………
………………………………………
………………………………………
………………………………………
……………………………………….
Temperature
Time
………………………………………
………………………………………
………………………………………
………………………………………
………………………………………
………………………………………
……………………………………….
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
91
4. …………………………………is the heat absorbed by a melting solid. The specific latent
heat of fusion is the quantity of the heat needed to change 1kg of solid to a liquid at its
melting point without any increase in ……………………….. The S.I unit of the specific
latent heat of fusion is Jkg-1
.
5. …………………………………... is heat of vaporisation is heat absorbed during boiling.
The specific latent heat of vaporisation is the quantity of heat needed to change 1kg of
liquid into gas or vapour of its boiling point without any change in ……………………..
The S.I unit is Jkg-1
.
water ice
water
gas
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
92
6. Explain the application of Specific Latent Heat above:
:
(d) Cooling of beverage
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
(e) Preservation of Food
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
(f) Steaming Food
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
(g) Killing of Germs and Bacteria
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
93
EXERCISE 4.3
Section A:
1. The graph in figure below shows how
the temperature of some wax changes as
it cools from liquid to solid. Which
section of the graph would the wax be a
mixture of solid and liquid?
A. PQ
B. QR
C. RS
D. ST
2. Figure show a joulemeter used for
measuring the electrical energy to melt
some ice in an experiment. To find the
specific latent heat of fusion of ice, what
must be measured?
A. The time taken for the ice to melt
B. The voltage of the electricity supply
C. The mass of water produced by
melting ice
D. The temperature change of the ice.
3. It is possible to cook food much faster
with a pressure cooker as shown above.
Why is it easier to cook food using a
pressure cooker?
A. More heat energy can be supplied to
the pressure cooker
B. Heat loss from the pressure cooker
can be reduced.
C. Boiling point of water in the pressure
cooker is raised
D. Food absorbs more heat energy from
the high pressure steam
4. Which of the following is not a
characteristics of water that makes it
widely used as a cooling agent?
A. Water is readily available
B. Water does not react with many
other substance
C. Water has a large specific heat
capacity
D. Water has a large density
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
2
5. Figure below shows the experiment set
up to determine the specific latent heat
of fusion of ice. A control of the
experiment is set up as shown in Figure
(a) with the aim of
A. determining the rate of melting of ice
B. ensuring that the ice does not melt
too fast.
C. determining the average value of the
specific latent heat of fusion of ice.
D. determining the mass of ice that
melts as a result of heat from the
surroundings
6. Scalding of the skin by boiling water is
less serious then by steam. This is
because…
A. the boiling point of water is less than
the temperature of steam
B. the heat of boiling water is quickly
lost to the surroundings
C. steam has a high specific latent heat.
D. Steam has a high specific heat
capacity.
SECTION B: Answer the question by showing the calculation
1. 300g of ice at 00C melts. How much energy is required for this
Question 2-7 are based on the following information
Specific heat capacity of water = 4 200 J kg-1
C-1
Specific heat capacity of ice = 2 100 J kg-1
C-1
Specific latent heat of fusion of ice = 3.34 X 105J kg
-1
Specific latent heat of vaporization of water = 2.26 X 106 J kg
-1
2. An immersion heater rated at 500 W is fitted into a large block of ice at 00C. How long
does it take to melt 1.5kg of ice?
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
2
3. 300 g of water at 400C is mixed with x g of water at 80
0C. The final temperature of the
mixture is 700C. Find the value of x
4. Calculate the amount of heat released when 2 kg of ice at 00C is changed into water at
00C.
5. Calculate the amount of heat needed to convert 3 kg of ice at 00C to water at 30
0C.
6. Find the amount of heat needed to convert 0.5 kg of ice at —150C into steam at 100
0C
7. Calculate the amount of heat needed to convert 100 g of ice at 00C into steam at 100
0C.
8. The specific latent heat of vaporization of water is 2300 kJ kg-1. How much heat will be
absorbed when 3.2 kg of water is boiled off at its boiling point.
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
3
UNDERSTANDING THE GAS LAW
By the end of this subtopic; you will be able to :
Explain gas pressure, temperature and volume in terms of the behaviour of gas molecules.
Determine the relationship between
(i) pressure and volume
(ii) volume and temperature
(iii) pressure and temperature
Explain absolute zero and the absolute/Kelvin scale of temperature
Solve problems involving pressure, temperature and volume of a fixed mass of gas
1. Complete the table below.
Property of gas Explanation
Volume,V
m3
Temperature,T
K (Kelvin)
Pressure,P
Pa(Pascal)
2. The kinetic theory of gas is based on the following assumptions:
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
4
4.4.1 Boyle’s Law
1. Boyle’s law states that……………………………………………………………………...
……………………………………………………............................................................................
2. Boyle’s law can be shown graphically as in Figure above
0
P
V
(a) P inversely proportional to V
0
P
1/V
(b) P directly proportional to 1/V
Small volume
molecules hit wall
more often, greater
pressure
P α 1
V
That is PV = constant
Or P1V1 = P2V2
Relationship between pressure and volume
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
5
3. The volume of an air bubble at the base of a sea of 50 m deep is 250cm3. If the
atmospheric pressure is 10m of water, find the volume of the air bubble when it reaches
the surface of the sea.
4.4.2 Charles’s Law
1. Charles’ law states ……………………………………………………………………….
…………………………………………………………………………………………… ………
The temperature -2730C is the lowest possible temperature and is known as the absolute zero of
temperature.
Relationship between
volume and temperature
Lower temperature
Higher temperature,
faster molecules,
larger volume to keep
the pressure constant
V α T
that is V = constant
T
PI=50m + 10m
V1=250cm3
P2= 10m
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
6
2. Fill the table below.
Temperature Celsius scale (0C) Kelvin Scale(K)
Absolute zero
Ice point
Steam point
Unknown point
3. Complete the diagram below.
4.4.3 Pressure’s Law
1. The pressure law states ………………………………………………………………....
………………………………………………………………………………………………..
θ/0C 100 -273
P α T
That is P = constant
T
Relationship between
pressure and temperature
Higher
temperature
molecules move
faster, greater
pressure
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
7
EXERSICE 4.4:Gas Law
1. A mixture of air and petrol vapour is injected into the cylinder of a car engine when the
cylinder volume is 100 cm3. Its pressure is then 1.0 atm. The valve closes and the mixture is
compressed to 20 cm3. Find the pressure now.
2. The volume of an air bubble at the base of a sea of 50 in deep is 200 cm3. If the atmospheric
pressure is 10 in of water, find the volume of the air bubble when it reaches the surface of
the sea.
3. The volume of an air bubble is 5 mm3 when it is at a depth of h in below the water surface.
Given that its volume is 15 mm3 when it is at a depth of 2 in, find the value of h.
(Atmospheric pressure = 10 m of water)
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
8
4. An air bubble has a volume of V cm3 when it is released at a depth of 45m from the water
surface. Find its volume (V) when it reaches the water surface. (Atmospheric pressure = 10
m of water)
5. A gas of volume 20m3 at 37
0C is heated until its temperature becomes 870C at constant
pressure. What is the increase in volume?
6. The air pressure in a container at 330C is 1.4 X 1O
5 N m2. The container is heated until the
temperature is 550C. What is the final air pressure if the volume of the container is fixed?
7. The volume of a gas is 1 cm3 at 15
0C. The gas is heated at fixed pressure until the volume
becomes triple the initial volume. Calculate the final temperature of the gas.
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
9
8. An enclosed container contains a fixed mass of gas at 250C and at the atmospheric pressure.
The container is heated and temperature of the gas increases to 980C. Find the new pressure
of the gas if the volume of the container is constant.(Atmospheric pressure = 1.0 X 105N
rn2)
9. The pressure of a gas decreases from 1.2 x 105 Pa to 9 x 10
5 Pa at 40
0C. If the volume of the
gas is constant, find the initial temperature of the gas.
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
10
PART A: CHAPTER 4
1. A 5kg iron sphere of temperature
500C is put in contact with a 1kg
copper sphere of temperature 273K
and they are put inside an insulated
box. Which of the following
statements is correct when they reach
thermal equilibrium?
D. A iron sphere will have a
temperature of 273K
E. The copper sphere will have a
temperature of 500C.
F. Both the sphere have the same
temperature.
G. The temperature of the iron
sphere will be lower than 500C
2. In the process to transfer heat from
one object to another object, which
of the following processes does not
involve a transfer to material?
A. Convection
B. Vaporisation
C. Radiation
D. Evaporation
3. When we use a microwave oven to
heat up some food in a lunch box, we
should open the lid slightly. Which
of the following explanations is
correct?
A. To allow microwave to go inside
the lunch box
B. To allow the water vapors to go
out, otherwise the box will
explode
C. To allow microwave to reflect
more times inside the lunch box
D. To allow microwave to penetrate
deeper into the lunch box.
4. Water is generally used to put out
fire. Which of the following
explanation is not correct?
A. Water has a high specific heat
capacity
B. Steam can cut off the supply of
oxygen
C. Water is easily available
D. Water can react with some
material
5. Given that the heat capacity of a
certain sample is 5000 J0C
-1. Which
of the following is correct?
A. The mass of this sample is 1kg.
B. The energy needed to increase
the temperature of 1 kg of this
sample is 5000 J.
C. The energy needed to increase
the temperature of 0.5kg of this
sample is 2500J.
D. The temperature of this sample
will increase 10C when 5 000 J
energy is absorbed by this
sample.
6. Which of the following statement is
correct?
A. The total mass of the object is
kept constant when fusion
occurs.
B. The internal energy of the object
is increased when condensation
occurs
C. Energy is absorbed when
condensation occurs.
D. Energy is absorbed when
vaporization occurs.
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
2
7. Water molecules change their states
between the liquid and gaseous states
A. only when water vapour is
saturated
B. at all times because evaporation
and condensation occur any time
C. only when the vapour molecules
produce a pressure as the same as
the atmospheric pressure
D. only when the water is boiling
8. Based on the kinetic theory of gas
which one of the following does not
explain the behaviour of gas
molecules in a container?
A. Gas molecules move randomly
B. Gas molecules collide elastically
with the walls of the container
C. Gas molecules move faster as
temperature increases
D. Gas molecules collide
inelastically with each other
9. A cylinder which contains gas is
compressed at constant temperature
of the gas increase because
A. the average speed of gas
molecules increases
B. the number of gas molecules
increases
C. the average distance between the
gas molecules increases
D. the rate of collision between the
gas molecules and the walls
increases
10. A plastic bag is filled with air. It is
immersed in the boiling water as
shown in diagram below.
Which of the following statements is
false?
A. The volume of the plastic bag
increases.
B. The pressure of air molecules
increases
C. The air molecules in the bag
move faster
D. The repulsive force of boiling
water slows down the movement
of air molecule
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
2
PART B;
1. A research student wishes to carry out an investigation on the temperature change of the
substance in the temperature range -500C to 50
0C. The instrument used to measure the
temperature is a liquid in glass thermometer.
Table 1
(a) (i) State the principle used in a liquid- in –glass thermometer.(1m)
........................................................................................................................................
(ii) Briefly explain the principle stated in (a)(i) (3m)
………………………………………………………………………………………….
………………………………………………………………………………………….
………………………………………………………………………………………….
(b) Table 1 shows the characteristic of 4 types of thermometer: A,B C and D. On the basis
of the information given in Table 1, explain the characteristics of, and suggest a suitable
thermometer for the experiment.(5 m)
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
……………………………………………………………………………………………..
Thermometer A B C D
Liquid Mercury Mercury Alcohol Alcohol
Freezing point of liquid (0C) -39 -39 -112 -112
Boiling point of liquid (0C) 360 360 360 360
Diameter of capillary tube Large Small Large Small
Cross section
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
3
(c) The length of the mercury column in uncalibrated thermometer is 6.0cm and 18.5 cm at
00C and 100
0C. respectively. When the thermometer is placed in a liquid, the length of
the mercury column is 14.0cm
(i) Calculate the temperature of the liquid
(ii) State two thermometric properties which can be used to calibrate a thermometer. (6m)
………………………………………………………………………………………………
………………………………………………………………………………………………
………………………………………………………………………………………………
2. A metal block P of mass 500 g is heated is boiling water at a temperature of 1000C.
Block P is then transferred into the water at a temperature of 300C in a polystyrene cup.
The mass of water in the polystyrene cup is 250 g. After 2 minutes, the water temperature
rises to 420C.
Assuming that the heat absorbed by the polystyrene cup and heat loss to the
surroundings are negligible.{Specific heat capacity of water 4 200 j kg-1
C-1
)
Calculate
(a) the quantity of heat gained by water the polystyrene cup
Figure 2
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
4
(b) the rate of heat supplied to the water
(c) the specific heat capacity of the metal block P
3. A student performs an experiment to investigate the energy change in a system. He
prepares a cardboard tube 50.0 cm long closed by a stopper at one end. Lead shot of
mass 500 g is placed in the tube and the other end of the tube is also closed by a stopper.
The height of the lead shot in the tube is 5.0 cm as shown in Figure 3.1. The student then
holds both ends of the tube and inverts it 100 times (Figure 3.2).
(a) State the energy change each time the tube is inverted.
…………………………………………………………………………………………..
…………………………………………………………………………………………..
(b) What is the average distance taken by the lead shot each time the tube is inverted?
Figure 3.1 Figure 3.2
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
5
(c) Calculate the time taken by the lead shot to fall from the top to the bottom of the tube.
(d) After inverting the tube 100 times, the temperature of the lead shot is found to have
increased by 30C.
i. Calculate the work done on the lead shot.
ii. Calculate the specific heat capacity of lead.
iii. State the assumption used in your calculation in (d)ii.
……………………………………………………………………………………………...
………………………………………………………………………………………………
……………………………………………………………………………………………….
PART C: EXPERIMENT
1. Before travelling on a long journey, Luqman measured the air pressure the tyre of his car
as shown in Figure (a) He found that the air pressure of the tyre was 200 kPa. After the
journey, Luqman measured again the air pressure of the tyre as shown in Figure (b) He
found that the air pressure had increase to 245 kPa. Luqman also found that the tyre was
hotter after the journey although the size of the tyre did not change.
Using the information provided by Luqman and his observations on air pressure in the
tyre of his car:
Figure (a) Figure (b)
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
6
Choose suitable apparatus such as pressure gauge, a round-bottomed flask and any other
apparatus that may he necessary. In your description, state clearly the following:
i. Aim of the experiment,
ii. Variables in the experiment,
iii. List of apparatus and materials,
iv. Arrangement of the apparatus,
v. The procedure of the experiment including the method of controlling the
manipulated variable and the method of measuring the responding variable,
vi. The way you would tabulate the data,
vii. The way you would analyse the data. [10 marks]
(a) State one suitable inference that can be made. [1 mark]
(b) State appropriate hypothesis for an investigation. [1 mark]
(c) Design an experiment to investigate the hypothesis stated in (b).
JPN Pahang Physics Module Form 4
Student’s Copy Chapter 4: Heat
7