Chapter 7 - Heat 1. Diagram 1 Below Shows The

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Chapter 7 - Heat

1. Diagram 1 below shows the relationship between the changes in state of matter inphysical processes.

Diagram 1

(a) Name the process marked

(i) W = .

(ii) X = .

(iii) Y = .

(iv) Z = .

[4 marks](b) Name the process that:

Absorb heat Release heat

(i) .(ii) .(iii) .

(i) (ii)

[3 marks]

(c) State a similarities for the process of boiling and evaporation.

.

[1 mark]

WY

Z

X


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2. Diagram 2 below shows an experiment set-up to study the transfer of heat.

Diagram 2

Table 2.1 below shows the results of the experiment.

Rods Time taken for thumbtacks to fall/secondsP 20Q 12R 120

Table 2.1

(a) Tick () the correct answer the transfer of heat through rod P, Q and R.

Transfer of heat

Conduction

Convection

Radiation

[1 mark]

( b ) Based on the table above, arrange the rods according to their conductivity

of heat in ascending order.

Rod ., rod ., rod [1 mark]

( c ) i. Rod P, Q and R are made from different materials. Which of them most

suitable to make handles for pots and pans .

..................................................................................................................

[1 mark]ii. Choose the correct reason for your answer.

The material is a poor conductor of heat

The material is a good conductor of heat

[2 marks]


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3. Diagram 3 shows the set-up of an experiment. The distance of the conical flasks

from the flame is the same . The Bunsen burner is lighted and left for ten minutes.

The readings of thermometer P and Q are recorded at the end of the experiment.

Diagram 3

a. i. Which thermometer shows a higher reading at the end of experiment ?

.

[ 1 mark ]

ii. Give one reason for your answer in a ( i ).

..

.

[ 1 mark ]

b. How does heat from the Bunsen burner reach thermometer ?

.[ 1 mark ]

c. During a hot day, Zanita chooses to wear a white wear instead of a black shirt .

Explain how this helps Zanita from feeling too hot.

.

..

.

[ 2 marks ]


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d. Malaysia is one of the states that situated at the hot region. Usually hot regions of

the world such as tropical regions experience hot weather . Suggest and explain a

method how the people in tropics can kept their house cool based on the concept

of heat radiation.

i. Method :

.

ii. Explanation :

.

.

..

[2 marks ]


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4.

A student carried out an experiment to study the conductivity of heat on differentmaterials.

The temperature of thermometers X and Y are recorded after is minutes.

Thermometer Initial temperature(C)

Final temperature(C)

Drop temperature(C)

X 100

Y 100

(a) State the variables involved in this experiment.

Tick () the correct answer.

Manipulated variable

Responding variable

Controlled variable Initial temperature of hot water,

Volume of the water

[2 marks]

(b) Based on the diagram, record the reading thermometer X and Y in table

above. [2 marks]


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(c) Calculate the drop in temperature in each thermometer X and Y. Record

your finding in table above. [2 marks]

(d) Based on the experiment, state the relationship between the manipulated

variable and the responding variable.

Different . conduct heat at different rates. [1 mark]

(d) Which sheet shows that heat flows faster from the conical flask?

.. [1 mark]

(f) i. If the iron sheet is replaced by a copper sheet, predict the temperature.

Most likely to be recorded on thermometer X the end of the experiment.

Circle one of the answer shown below:

70C 76C 78C

[1 mark]

ii. Give your reason for your answer.

is better heat conductor than .. [2 marks]


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5. Diagram 5 shows an experiment set-up to study the transfer of heat.

Diagram 5

Table 5.1 shows the result of the experiment.

Rod Time taken for thumbtacks to fall/seconds

P 20

Q 12

R 120

Table 5.1

(a) State how does heat flow through rod P, Q and R.

..(1 mark)

(b)( i) Arrange the rods according to their conductivity of heat inascending order.

Rod Rod Rod (1mark)

(ii) Explain your answer in (b)(i).

..(2 marks)


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(c)(i) Rod P, Q and R are made from different materials.

State the material that is most suitable to make cooking utensils handles.

...............................................................................................................(1mark)

(ii) State the reason for your answer.

.

.

.

(2 marks)


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6.. A student found that when he wears a darker coloured shirt and steps into the sun

rays, he feels hotter and sweats more as shown in figure.

a) i. Based on the observations given, state the difference in the amount of heat

received by the student in Situation A and Situation B.

(1 mark)

ii. State one hypothesis based on the observation in (a)

.

(1 mark)

Situation A Situation B


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b) A student carried out an experiment to investigate the situation. Diagram below

shows the arrangement of apparatus for the experiment.

Procedure:

1. The initial temperature of the water in each of the two tins is recorded.

2. The Bunsen burner is lighted and left burning for 15 minutes.

3. The final temperature of the water in each of the two tins is recorded.

i. Record the temperature readings in the spaces provided.

(2 marks)


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ii. Complete table by recording the temperature readings for the respective tin.

Temperature /0 CTin

Initial Final Rise

X

Y

(2 marks)

(c) Based on readings draw a bar chart which shows the temperature with thedifference surface.

X Y

Temperaturerises /

0C

Type of surface (2marks)


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(d) State the variables involved in this experiment.

Manipulated variable

Responding variable

Controlled variable

(3 marks)

(e) Based on the experiment,state the relationship between the brightness of

the surface and the amount of the heat absorbed.

.

(1 mark)

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Chapter 7 - Heat 1. Diagram 1 Below Shows The