AQA GCSE Physics Physics Paper 2 (Foundation), June 2023: Question 9
17 marks · Standard Demand difficulty · Extended Answer
Investigate infrared waves, infrared emission and absorption by different surfaces, and fluid pressure calculations.
Practise this questionQuestion
Question text
09 Infrared waves are transverse waves.
09.1 Complete the sentence.
[1 mark]
In a transverse wave, the direction of oscillation is
to the direction of energy transfer by the wave.
A student investigated how the colour of a surface affects the rate at which the
surface emits infrared radiation.
Figure 23 shows some of the equipment used.
Figure 23
09.2 The student wrote the following hypothesis:
‘The black-coloured flask will emit more infrared radiation than the
silver-coloured flask during 10 minutes of cooling.’
Describe a method to test this hypothesis.
[6 marks]
09.3 When will the flasks emit infrared radiation at the greatest rate?
Give a reason for your answer.
[2 marks]
Tick ( ) one box.
During the 1st minute
During the 5th minute
During the 9th minute
Reason
Another student investigated the absorption of infrared radiation by different
surface colours.
The student filled four hollow metal cubes with cold water.
Each cube was the same size but had a different surface colour.
The cubes were then placed the same distance from an infrared heater.
After 10 minutes, the student measured the temperature increase of the water inside
each cube.
09.4 What was the dependent variable in this investigation?
[1 mark]
09.5 Table 2 shows the results.
Table 2
Temperature increase after
Surface colour of the cube
10 minutes in °C
Matt white 3.0
Shiny white 2.0
*38* Matt black 6.5
Shiny black 4.0
Give two conclusions that can be made from the results in Table 2.
[2 marks]
Figure 24 shows one of the cubes. The cube is filled with water.
The weight of the water exerts a pressure on the bottom of the cube.
*39* Figure 24
Use the Physics Equations Sheet to answer questions 09.6 and 09.7.
09.6 Which equation correctly links area, force and pressure?
[1 mark]
Tick ( ) one box.
pressure = force × area2
pressure = force × area
force
pressure =
area
area
pressure = 41
force
09.7 The water pressure at the bottom of the cube is 1500 Pa.
Calculate the force of the water on the bottom of the cube.
[4 marks]
Force = N
Mark scheme
Show the mark scheme
Question 9
AO /
Question Answers Extra information Mark
Spec. Ref.
09.1 perpendicular 1 AO1
4.6.1.1
AO /
Question Answers Mark
Spec. Ref.
Level 3: The method would lead to the production of a valid 5-6 AO3
09.2 outcome. The key steps are identified and logically sequenced.
Level 2: The method would not necessarily lead to a valid 3-4 AO1
outcome. Most steps are identified, but the method is not fully
logically sequenced.
Level 1: The method would not lead to a valid outcome. Some 1-2 AO1
relevant steps are identified, but links are not made clear.
No relevant content 0
Indicative content 4.6.2.2
Method:
• heat the water / kettle
• add an equal volume of (hot) water to each flask
• insert a thermometer into each flask
• record the initial temperature from both flasks
OR
• place an IR detector near each flask
• the distance between the IR detector and the flask should be the
same each time
• record initial reading from IR detectors
• (and) start a stop clock
• record the temperatures / readings after 10 minutes from both
flasks
• calculate the change in temperatures / readings during the 10
minutes
• compare the results to test the hypothesis
to access level 3 the method must allow the correct consideration
of a temperature decrease for both flasks or the correct comparison
of IR detected from both flasks
22 AO /
Spec. Ref.
09.3 during the 1st minute 1 AO2
there is the greatest allow highest temperature or 1 AO1
temperature difference (between hottest
the hot water and the 4.6.3.1
surroundings)
MP 2 dependent on scoring
MP1
AO /
Spec. Ref.
09.4 the temperature (increase / allow the final temperature 1 AO1
change after 10 minutes) 4.6.2.2
do not allow temperature
decrease
AO /
Spec. Ref.
09.5 black surfaces absorb more allow black surfaces have a 1 AO3
(infrared than white surfaces) greater temperature increase 4.6.2.2
(than white surfaces) 4.6.3.1
matt surfaces absorb more allow matt surfaces have a 1
(infrared) than shiny surfaces of greater temperature increase
the same colour than shiny surfaces of the same
colour
if no other marks scored, allow 1
mark for matt black surface is
the best absorber and shiny
white surface is the worst
absorber
if no other marks scored, allow 1
mark for matt black has the
greatest temperature increase
and shiny white has the smallest
temperature increase
AO /
Question Answers Extra information Mark 23
Spec. Ref.
force 1 AO1
09.6 pressure =
area 4.5.5.1.1
AO /
Spec. Ref.
09.7 area of base = 0.0144 (m2) do not allow this or subsequent 1 AO2
marks unless base area is used 4.5.5.1.1
F this mark may be awarded if 1
1500 =
0.0144 base area is incorrectly
calculated
this mark may be awarded if 1
F = 1500 × 0.0144
base area is incorrectly
calculated
this mark may be awarded if 1
F = 21.6 (N)
base area is incorrectly
calculated
allow 22 (N)
Total Question 9 17
How to answer it
Infrared Waves, Emission, Absorption, and Pressure
What this question tests
This question assesses your knowledge of electromagnetic waves (specifically infrared radiation), planning a scientific experiment (controlling variables and logging data), interpreting tables of results, and applying the pressure-force-area equation. You will need to demonstrate recall of wave properties, experimental design skills (Level of Response question), and mathematical calculation techniques.
Wave Properties
✅ Correct Answer
perpendicular
💡 Key Knowledge
- In transverse waves, oscillations are at right angles (perpendicular) to the direction of energy transfer.
- Examples include all electromagnetic waves (like infrared) and ripples on water surfaces.
Planning an Investigation (6 Marks)
Describe a method to test the hypothesis: 'The black-coloured flask will emit more infrared radiation than the silver-coloured flask during 10 minutes of cooling.'
🧠 Exam Technique (Level of Response)
To reach Level 3 (5–6 marks), your method must be logical, repeatable, and allow a valid comparison. Key elements needed:
- Use identical flasks (one black, one silver) filled with an equal volume of hot water (from a kettle).
- Measure and record initial temperatures using thermometers (or use an infrared detector kept at the exact same distance from each flask).
- Use a stopwatch to time 10 minutes, then record the final temperatures.
- Calculate the temperature decrease (or compare temperature drops) to test the hypothesis.
❌ Common Errors
- Failing to control variables (e.g., using different volumes of water or starting at different temperatures).
- Forgetting to state that the distance between the IR detector and each flask must be identical.
- Vague descriptions like "measure the heat" instead of measuring temperature change over a set time.
Rate of Emission
✅ Correct Answer
Tick: During the 1st minute
Reason: There is the greatest temperature difference between the hot water and the surroundings.
💡 Key Knowledge
The rate of infrared emission depends directly on the temperature difference between the object and its surroundings. The hotter the object relative to its environment (or the larger the temperature gradient), the faster it emits thermal radiation.
Identifying Variables
✅ Correct Answer
The temperature increase (or temperature change after 10 minutes).
❌ Common Errors
- Writing just "temperature" without specifying that it is the increase or change.
- Confusing the dependent variable with independent variables (surface colour of the cube).
Drawing Conclusions from Data
✅ Correct Answers (Any two)
- Black surfaces absorb more infrared radiation than white surfaces.
- Matt surfaces absorb more infrared radiation than shiny surfaces of the same colour.
- Matt black is the best absorber / shiny white is the worst absorber.
🧠 Exam Technique
When answering data-interpretation questions, always compare directly using the numbers or trends in the table. Back up your scientific statements using evidence from the results (e.g., Matt black had a temperature increase of 6.5 °C compared to shiny white at 2.0 °C).
Pressure Equation
✅ Correct Answer
Tick: pressure = force / area
💡 Key Knowledge
Standard formula from the Physics Equations Sheet: p = F / A where pressure ( p ) is in Pascals (Pa), force ( F ) is in Newtons (N), and area ( A ) is in square metres ( m² ).
Pressure Calculation
The water pressure at the bottom of the cube is 1500 Pa. The cube is square with side lengths of 0.12 m. Calculate the force of the water on the bottom of the cube.
📐 Step-by-Step Calculation
- Calculate the area of the base:
Area = 0.12 m × 0.12 m = 0.0144 m² - Rearrange the pressure equation:
Force = Pressure × Area ( F = p × A ) - Substitute the values:
Force = 1500 × 0.0144 - Calculate final answer with units:
Force = 21.6 N (or 22 N if rounded)
❌ Common Calculation Traps
- Area calculation error: Forgetting to square the side length (calculating 0.12 + 0.12 or multiplying by 4 instead of 0.12 × 0.12). Note: The mark scheme allows subsequent calculation marks if your base area was wrong, provided you use it correctly!
- Transposition error: Dividing pressure by area instead of multiplying when calculating force.
Topics
Physics · Required Practicals · P5: Forces · P6: Waves · Required Practicals
Question and mark scheme from the AQA GCSE Physics examination, Physics Paper 2 (Foundation), June 2023. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.