JB2014 Physics Module Form 4Student’s Copy 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
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
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Thermal equilibrium :Keseimbang
an terma
CHAPTER 4: HEAT
……………………………………………………………………………..
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…………………………………………………………………………………….
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…………………………………………………………………………………….
…………………………………………………………………………………….
………….. rate of energy transfer
Hot object
Cold object
………….. rate of energy transfer
Equivalent to Equivalent to
No net heat transfer
A B
JB2014 Physics Module Form 4Student’s Copy 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. 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 contactB. P and Q are in thermal equilibriumC. Energy is transferred from P to QD. Energy is transferred from Q to P
2. When does the energy go when a cup of hot tea cools?
A. It warms the surroundingsB. It warms the water of the teaC. It turns into heat energy and
disappears.
3. Which of the following temperature corresponds to zero on the Kelvin scale?A. 2730 CB. 00CC. -2730 CD. 1000 C
4. How can the sensitivity of a liquid- in –glass thermometer be increased?
2
……………………………..…
…………………………………
l0 : length of mercury at ice pointl100 : length of mercury at steam pointlθ : length of mercury at θ point
Temperature, θ =lθ - l0
l100 - l0x 1000C
JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
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 tubeD. Using a thinner-walked bulb
5. Which instrument is most suitable for measuring a rapidly changing temperature?A. Alcohol-in –glass thermometerB. ThermocoupleC. Mercury-in-glass thermometerD. 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
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JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
3. 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
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JB2014 Physics Module Form 4Student’s Copy 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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JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
2. What do you mean by heat and temperature?
……………………………………………………………………………………………....
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: 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.
6
Heat capacityMuatan haba
Specific heat capacityMuatan haba tentu
Specific heat capacity , c = Q__
m∆θ
JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
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) ....................................................................................................................................
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Electrical energy Heat energyPt = mcθ
Heater
Power = P
…………energy
…………..energy
…………..energy
Object falls from
A high position
Moving object stopped
due to friction
Power = P
Heat energymgh= mcθ
Heat energy½ mv2= mcθ
Small value of c Big value of cTwo object of equal mass
Equal rate of heat supplied
………. increase in temperature
……………. increase in temperature
JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
(b) Household apparatus and utensils
………………………………………………………………………………………...
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(c) Sea breeze
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(d) Land breeze
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JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
Exercise 4.2
SECTION A : Choose the best answer
1. The change in the temperature of an object does not depend onA. the mass of the objectB. the type of substance the object is
made ofC. the shape of the objectD. 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 waterB. is less dense than waterC. has a larger specific heat capacity
than waterD. 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 heatB. To reduce the consumption of
electrical energyC. 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).
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JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
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 a 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).
5. 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 kg-1 C-1)
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JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
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.
…………………………………………………………………………………………..
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A
B
1000C 200C
5kg
2.25kg
JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
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
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SolidSolidification
Latent heat …………
BoilingLatent heat …………. Condensation
Latent heat …………
Liquid
Gas
Temperature
Time
………………………………………
………………………………………
………………………………………
………………………………………
………………………………………
………………………………………
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JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
(b) Boiling
(c) Solidification
(d) Condensation
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Temperature
Time
………………………………………
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Temperature
Time
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Temperature
Time
………………………………………
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………………………………………
………………………………………
………………………………………
………………………………………
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JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
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.
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water ice
watergas
JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
6. Explain the application of Specific Latent Heat above:
:
(d) Cooling of beverage
………………………………………………………………………………………………
………………………………………………………………………………………………
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(e) Preservation of Food
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(f) Steaming Food
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(g) Killing of Germs and Bacteria
………………………………………………………………………………………………
………………………………………………………………………………………………
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JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
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. PQB. QRC. RSD. 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 meltB. The voltage of the electricity supplyC. The mass of water produced by
melting iceD. 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 availableB. Water does not react with many
other substanceC. Water has a large specific heat
capacityD. Water has a large density
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JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
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 iceB. 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 steamB. the heat of boiling water is quickly
lost to the surroundingsC. 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 0 0C.
How long does it take to melt 1.5kg of ice?
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JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
3. 300 g of water at 400C is mixed with x g of water at 800C. 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
300C.
6. Find the amount of heat needed to convert 0.5 kg of ice at —150C into steam
at 1000C
7. Calculate the amount of heat needed to convert 100 g of ice at 00C into steam
at 1000C.
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.
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JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
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)
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JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
2. The kinetic theory of gas is based on the following assumptions:
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4.4.1 Boyle’s Law
1. Boyle’s law states that……………………………………………………………………...
……………………………………………………............................................................................
2. Boyle’s law can be shown graphically as in Figure above
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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 P1V
1 = P
2V
2
Relationship between pressure and volume
JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
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.
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Relationship between volume and temperature
Lower temperature
Higher temperature, faster molecules, larger volume to keep the pressure constant
V α Tthat is V = constant
T
PI=50m + 10m
V1=250cm3
P2= 10m
JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
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
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θ/0C100-273
P α TThat is P = constant
T
Relationship between pressure and temperature
Higher temperature molecules move faster, greater pressure
JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
1. The pressure law states ………………………………………………………………....
………………………………………………………………………………………………..
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)
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JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
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 370C 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 1O5 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?
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JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
7. The volume of a gas is 1 cm3 at 150C. The gas is heated at fixed pressure until the
volume becomes triple the initial volume. Calculate the final temperature of the gas.
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 105 Pa at 400C. If the volume
of the gas is constant, find the initial temperature of the gas.
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JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
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 273KE. 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. ConvectionB. VaporisationC. RadiationD. 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 boxB. 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
capacityB. Steam can cut off the supply of
oxygenC. Water is easily availableD. 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.
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JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
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.
7. Water molecules change their states between the liquid and gaseous statesA. only when water vapour is
saturatedB. at all times because evaporation
and condensation occur any timeC. 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 containerC. Gas molecules move faster as
temperature increasesD. Gas molecules collide
inelastically with each other
9. A cylinder which contains gas is compressed at constant temperature of the gas increase becauseA. the average speed of gas
molecules increasesB. the number of gas molecules
increasesC. the average distance between the
gas molecules increasesD. 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
increasesC. The air molecules in the bag
move fasterD. The repulsive force of boiling
water slows down the movement of air molecule
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JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
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 500C. 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)
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(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)
…………………………………………………………………………………………
………………………………………………………………………………………………
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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
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JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
………………………………………………………………………………………………
………………………………………………………………………………………………
…..
(c) The length of the mercury column in uncalibrated thermometer is 6.0cm and 18.5 cm at
00C and 1000C. 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)
………………………………………………………………………………………………
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………………………………………………………………………………………………
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
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Figure 2
JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
(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.
…………………………………………………………………………………………..
…………………………………………………………………………………………..
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Figure 3.1 Figure 3.2
JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
(b) What is the average distance taken by the lead shot each time the tube is
inverted?
(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.
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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:
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JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
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]
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Figure (a) Figure (b)(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).
JB2014 Physics Module Form 4Student’s Copy Chapter 4: Heat
33