AQA GCSE Physics Physics Paper 1 (Higher), June 2024: Question 8
8 marks · Standard Demand difficulty · Short Answer
Explain why pressure increases when a syringe's volume is decreased, identify the effect of temperature increase on particles, and calculate temperature change using specific heat capacity.
Practise this questionQuestion
Question text
08 A student investigated how the pressure in a fixed mass of air varies with the volume
of the air.
Figure 12 shows the equipment used.
Figure 12
08.1 When the plunger was pushed slowly into the syringe, the pressure in the
syringe increased.
The temperature of the air remained constant.
Explain why the pressure increased.
[3 marks]
A fire piston is a special type of syringe that can be used to start fires.
Figure 13 shows a fire piston.
Figure 13
The plunger is pushed quickly downwards and compresses the air.
When the air is compressed quickly, the temperature of the air increases.
08.2 How does an increase in temperature affect the air particles inside the piston?
[1 mark]
Tick ( ) one box.
The mean kinetic energy of the particles increases.
The mean potential energy of the particles increases.
The mean separation of the particles increases.28
08.3 When the air is hot enough, a small piece of cotton wool in the piston catches fire.
The energy transferred to the air in the piston is 0.0130 J.
The mass of air in the piston is 2.60 × 10–8 kg.
specific heat capacity of air = 1.01 kJ/kg °C
*27* Calculate the temperature change of the air.
Use the Physics Equations Sheet.
[4 marks]
Temperature change = °C
Mark scheme
Show the mark scheme
Question 8
AO /
Question Answers Extra information Mark
Spec. Ref.
08.1 (air) particles are closer together ignore reference to kinetic 1 AO1
energy of particles 4.3.3.2
ignore reference to
concentration of air particles
(so) frequency of collision do not credit MP2 if linked to an 1
between air particles and increase in kinetic energy
syringe walls increased
larger (total) force on a smaller allow larger force per unit area 1
(surface) area
if no other marks score allow
1 mark for pressure increases
because volume decreases and
pV = constant
AO /
Spec. Ref.
08.2 the mean kinetic energy of the 1 AO1
particles increases 4.3.3.1
AO /
Question Answers Extra information Mark Spec.
08.3 c = 1010 (J/kg °C) allow full credit for a correct 1 AO2Ref.
method using E = 0.0000130 4.1.1.3
(kJ) 4.3.2.2
0.0130 = 2.60×10–8 × 1010 × Δθ allow a correct substitution of an 1
incorrectly / not converted value
of c
0.0130 allow a correct rearrangement of 1
∆θ = –8 an incorrectly / not converted
(2.60 × 10 × 1010)
value of c
Δθ = 495 (°C) allow an answer consistent with 1
an incorrectly / not converted
value of c
allow a correct answer given to
more than 3 sig figs
Total Question 8 8
How to answer it
Particle Model of Matter & Energy Study Guide
What this question tests
This question assesses your understanding of the particle model of matter, specifically how pressure relates to volume and particle collisions in gases at a constant temperature, the relationship between temperature and particle kinetic energy, and applying the specific heat capacity equation to calculate temperature changes.
Part 08.1: Explaining Pressure and Volume
When the plunger was pushed slowly into the syringe, the pressure increased. Explain why. (3 marks)
✅ Correct Answer Structure
- Air particles are closer together (smaller volume).
- The frequency of collisions between air particles and the syringe walls increases.
- This creates a larger force on a smaller surface area, resulting in higher pressure.
💡 Key Knowledge
- Pressure in a gas is caused by particles colliding with container walls.
- If volume decreases, particles have less distance to travel between walls, causing them to collide more often.
- Boyle's Law concept: Pressure × Volume = Constant (at constant temperature).
🧠 Exam Technique
- This is a classic 3-mark causal chain question. You must explain step-by-step: distance/volume change → collision frequency → force/area.
- Alternative acceptable marking point: Mentioning that pressure increases because volume decreases and pV = constant .
❌ Common Errors
- Stating that particle speed or kinetic energy increases (the question states temperature remains constant!).
- Failing to link collision frequency specifically to the walls of the container.
Part 08.2: Temperature and Particle Energy
How does an increase in temperature affect the air particles inside the piston? Tick one box. (1 mark)
✅ Correct Answer
The mean kinetic energy of the particles increases. (Tick the first box)
💡 Key Knowledge
Temperature is directly proportional to the mean (average) kinetic energy of the particles in a system. When a gas is compressed quickly, work is done on it, increasing its internal energy and temperature.
Part 08.3: Specific Heat Capacity Calculation
Calculate the temperature change of the air. (4 marks)
Given data: Energy ( E ) = 0.0130 J, Mass ( m ) = 2.60 × 10⁻⁸ kg, Specific heat capacity ( c ) of air = 1.01 kJ/kg °C
📐 Step-by-Step Calculation
- Convert units: Convert c from kJ/kg °C to J/kg °C.
1.01 kJ = 1010 J, so c = 1010 J/kg °C . - Recall equation:
E = m × c × Δθ - Substitute values:
0.0130 = (2.60 × 10⁻⁸) × 1010 × Δθ - Rearrange and solve for Δθ:
Δθ = 0.0130 / ((2.60 × 10⁻⁸) × 1010)
Δθ = 0.0130 / 0.00002626
Δθ = 495 °C
❌ Common Calculation Traps
- Unit prefix trap: Forgetting to convert kJ to J by multiplying by 1000. Examiners allow error-carried-forward (ECF) if you forgot to convert, but getting it right gets full marks!
- Standard form input errors: Entering numbers incorrectly into the calculator with powers of 10. Always use brackets around scientific notation.
Topics
Physics · P1: Energy · P3: Particle Model of Matter
Question and mark scheme from the AQA GCSE Physics examination, Physics Paper 1 (Higher), June 2024. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.