Aristo Science for the New Century Answers to Assignment book (2023 Updated Version)

Unit 5 Energy

5.1
(p.30) A 1. T
2. F
3. T
4. F
5. F
(p.30) B 1. C
2. C
3. D
4. B
(p.31) C 1. (a) electrical energy (1m)
(b) (i) light energy (1m)
(ii) thermal energy (1m)
(iii) sound energy (1m)
(c) kinetic energy (1m)
(d) chemical energy (1m)
(e) (i) thermal energy (1m)
(ii) light energy (1m)
(f) potential energy (1m)

5.2
(p.32) A 1. T
2. T
3. F
4. F
(p.32) B 1. B
2. A
3. C
4. D
(p.34) C 1. (a) light energy (1m) à chemical energy (1m)
(b) potential energy (1m) à kinetic energy (1m)
(c) chemical energy (1m) à thermal energy (1m) + light energy (1m)
(d) kinetic energy (1m) à kinetic energy (1m) + sound energy (1m)
2. (a) (i) sound energy (1m)
(ii) thermal energy (1m)
(iii) sound energy (1m)

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 Aristo Science for the New Century Answers to Assignment book (2023 Updated Version)

(iv) kinetic energy (1m)

(v) sound energy (1m)
(vi) thermal energy (1m)
(vii) kinetic energy (1m)
(b) (i)

(ii) 8/10 × 100% (1m) = 80% (1m)

5.3
(p.36) A 1. T
2. T
3. F
4. F
5. F
(p.36) B 1. C
2. A
3. B
4. D
5. B
6. D
(p.38) C 1. (a) (i) good (1m)
(ii) Heat (1m)
(iii) poor (1m)

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 Aristo Science for the New Century Answers to Assignment book (2023 Updated Version)

(iv) cannot be transferred easily (1m)

(b) poor absorbers (1m)
(c) (i) poor conductor (1m)
(ii) cannot be transferred easily from the surroundings (1m)
2. (a) This is to ensure that the experiment is a fair test. (1m)
(b) Conduction (1m)
(c) Copper (1m)
(d) Copper rod (1m)
3. (a) Stopper (1m)
(b) The silver surfaces of the glass walls (1m)
(c) (i) Flask P (1m)
(ii) air (1m)
(iii) conduction (1m)
(iv) convection (1m)

5.4
(p.41) A 1. F
2. T
3. T
(p.41) B 1. A
2. C
3. B
4. D
(p.42) C 1. (a) Non-renewable energy sources: Fossil fuels (1m), nuclear power
(1m)
Renewable energy sources: Biomass energy (1m), hydroelectric
power (1m), solar energy (1m), wind power (1m)
(b) Non-renewable energy sources take a very long time to replenish
after they are used. (1m)
Renewable energy sources can be replenished in a short period of
time. (1m)
2. (a) It causes less air pollution. (1m)
The energy supply is affected by the day length and sunlight
intensity. (1m)

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 Aristo Science for the New Century Answers to Assignment book (2023 Updated Version)

(b)

(c) July (1m)

(d) No, (1m) Hong Kong is a small city with limited land for the
installation of solar panels. (1m) / Yes, (1m) there is abundant
sunshine throughout the year in Hong Kong. People can install the
solar panels on the rooftop of the buildings. (1m) (Or any other
reasonable answers)

Integrated Exercise
(p.44) A 1. F
2. F
3. T
4. F
5. T
6. F
7. T
8. F
(p.44) B 1. A
2. C
3. A
4. D
5. C
6. D
7. D
8. D
9. B
10. C

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 Aristo Science for the New Century Answers to Assignment book (2023 Updated Version)

(p.47) C 1. (a) (1). (1m) A moving object has more kinetic energy than an object
at rest. (1m)
(b) This is because the hot air rises and a convection current is set up.
(1m)
2. (a) chemical (1m)
thermal (1m)
kinetic (1m)
thermal (1m)
kinetic (1m)
(b) Convection (1m) / Convection and radiation (1m)
(c) Copper. (1m) It is a better conductor than glass so that heat can be
transferred to the water more effectively. (1m)
3. (a) (i) Plastic is a poor conductor of heat (1m) and helps reduce
heat loss by conduction. (1m)
(ii) Glass can help trap heat from the Sun inside the solar cooker.
(1m)
(b) (i) Angle of incoming light to the solar cooker (1m)
(ii) The size of the egg (1m)
(iii) the angle of incoming light to the solar cooker is 90°
(2m)
(c) Paint the inner surface of the solar cooker black (1m) because
black surface is a good absorber of radiation. (1m) (Or any other
reasonable answers)
4. (a) (i) 40/100 × 100% (1m) = 40% (1m)
(ii) 28/100 × 100% (1m) = 28% (1m)
(iii) 16/100 × 100% (1m) = 16% (1m)
(iv) Fossil fuels (1m)
(b) Renewable energy sources cause less air pollution. (1m)
Renewable energy sources can be replenished in a short period of
time. (1m)
(c) It is limited to locations that are open and windy. (1m) (Or any
other reasonable answers)
(d) Choosing an electrical appliance with an energy label of higher
grade to save energy (1m)
Using public transport instead of private vehicles (1m) (Or any
other reasonable answers)

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 Aristo Science for the New Century Answers to Assignment book (2023 Updated Version)

Spelling Corner
(p.52) 1. KINETIC
2. R A D I A T I O N
3. F O S S I L
4. R E N E W A B L E

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