AQA GCSE Combined Science: Trilogy Physics Paper 1 (Foundation), 2024: Question 2
9 marks · Standard Demand difficulty · Short Answer
Identify geothermal energy characteristics, calculate thermal energy change and height from GPE, and explain fossil fuel disadvantages.
Practise this questionQuestion
Question text
02 Figure 2 shows an outdoor swimming pool.
The water in the swimming pool comes from the sea.
Figure 2
The water in the pool is heated using a geothermal energy resource.
02.1 Which of the following describes a geothermal energy resource?
[1 mark]
Tick ( ) one box.
A non-renewable energy resource with high carbon emissions.
A non-renewable energy resource with low running costs.
A renewable energy resource that uses hot rocks underground.
A renewable energy resource that uses the tides.7
02.2 15 kg of seawater is heated before it is added to the pool.
specific heat capacity of seawater = 3800 J/kg °C
Calculate the change in thermal energy of 15 kg of seawater when its temperature is
increased by 9.0 °C.
Use the equation:
change in thermal energy = mass × specific heat capacity × temperature change
*06* [2 marks]
Change in thermal energy = J
02.3 The energy transferred from 1.0 m2 of the surface of the pool to the air is
80 J each second.
The surface area of the pool is 120 m2.
Calculate the energy transferred from the whole surface of the pool to the air
each second.
[1 mark]
Energy transferred each second =8 J
02.4 Which of the following units is the same as 1 J/s?
[1 mark]
Tick ( ) one box.
1 N
1 Pa
1 W
02.5 The pool is above sea level.
5.0 kg of water is pumped from sea level into the pool.
The water gains 196 J of gravitational potential energy.
gravitational field strength = 9.8 N/kg
Calculate the height of the pool above sea level.
Use the equation:
gravitational potential energy
height =
mass × gravitational field strength
[2 marks]
Height = m
02.6 The water in some swimming pools is heated by burning fossil fuels.
Explain one environmental disadvantage of burning fossil fuels.
[2 marks]
Mark scheme
Show the mark scheme
Question 2
AO /
Question Answers Extra information Mark
Spec. Ref.
02.1 a renewable energy resource 1 AO1
that uses hot rocks underground 6.1.3
AO /
Spec. Ref.
02.2 ΔE = 15 × 3800 × 9.0 1 AO2
6.3.2.2
513 000 (J) 1 6.1.1.3
AO /
Spec. Ref.
02.3 9600 (J) 1 AO2
6.1.1.4
AO /
Spec. Ref.
02.4 1 W 1 AO1
6.1.1.4
AO /
Spec. Ref.
02.5 196 1 AO2
height =
5.0 × 9.8 6.1.1.2
4 (m) – allow 4.0 (m) – 1 –
AO /
Spec. Ref.
ignore references to pollution
02.6 EITHER AO1
releases carbon dioxide 1 6.1.3
which contributes to global allow climate change for global 1
warming warming 9
allow which is a greenhouse gas
allow which contributes to the
greenhouse effect
OR
releases sulfur / nitrogen dioxide allow other oxides of nitrogen
(1)
which causes acid rain (1)
OR
releases soot (1) allow carbon for soot
allow particulates
which can cause global dimming allow reduces air quality
(1) allow causes smog
Total Question 2 9
How to answer it
Energy Resources and Heating Calculations
What this question tests
This question assesses your understanding of energy resources (renewable vs non-renewable), your ability to perform thermal energy and gravitational potential energy calculations using provided equations, and your knowledge of the environmental impacts of fossil fuels.
Geothermal Energy Definition
Correct Answer
A renewable energy resource that uses hot rocks underground.
Key Knowledge
- Geothermal: "Geo" (Earth) + "Thermal" (Heat).
- It is renewable because the heat from the Earth's core is not "used up."
Specific Heat Capacity Calculation
Step-by-Step Calculation
- Identify the values: Mass = 15 kg, SHC = 3800 J/kg °C, Temp Change = 9.0 °C.
- Substitute into the equation: 15 × 3800 × 9.0
- Calculate: 513,000 J
Exam Technique
Always write out the substitution step even if you use a calculator. If you make a typing error but the substitution is correct, you still get 1 mark!
Mark 1: Correct substitution of values.
Mark 2: Correct final answer.
Power and Units
02.3 Calculation
Energy per m² = 80 J
Total area = 120 m²
80 × 120 = 9600 J
02.4 Units
Which unit is the same as 1 J/s?
1 W (Watt)
Key Knowledge: Power
Power is the rate of energy transfer. 1 Watt is defined as 1 Joule of energy transferred every second.
Calculating Height (GPE)
Step-by-Step Calculation
- Identify values: GPE = 196 J, Mass = 5.0 kg, g = 9.8 N/kg.
- Set up the fraction: 196 / (5.0 × 9.8)
- Simplify the bottom: 5.0 × 9.8 = 49
- Final division: 196 / 49 = 4 m
Common Calculation Trap
When using a calculator for fractions like this, students often type 196 ÷ 5.0 × 9.8 . This is wrong because the calculator will divide by 5 and then multiply the whole thing by 9.8.
Correct way: Use brackets 196 ÷ (5.0 × 9.8) or calculate the bottom number first!
Environmental Disadvantages
Top Scoring Answers
- Carbon Dioxide: Releases CO₂ which contributes to global warming.
- Sulfur Dioxide: Releases SO₂ which causes acid rain.
- Particulates: Releases soot/smoke which causes global dimming or respiratory issues.
Examiner Warning
Do NOT just write "it causes pollution." This is too vague for GCSE and will score zero marks. You must name the specific pollutant or the specific effect (e.g., global warming).
Structure your answer
This is a 2-mark "Explain" question.
1. Name the pollutant (e.g., Carbon dioxide).
2. State the consequence (e.g., leads to the greenhouse effect/global warming).
Topics
Physics · P1: Energy · P2: Electricity
Question and mark scheme from the AQA GCSE Combined Science: Trilogy examination, Physics Paper 1 (Foundation), 2024. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.