AQA GCSE Combined Science: Trilogy Physics Paper 2 (Foundation), 2022: Question 2
11 marks · Standard Demand difficulty · Short Answer
Describe and evaluate an investigation into how surface colour affects the emission of infrared radiation using flasks and a Leslie Cube.
Practise this questionQuestion
Question text
02 A student investigated how the colour of a surface affects the power of the infrared
radiation emitted by the surface.
Figure 2 shows the equipment used.
Figure 2
The infrared detector measures the power of the infrared radiation emitted by
the flasks.
02.1 The student poured hot water into each flask.
What should the student do to reduce the risk of burning herself with the hot water?
[1 mark]
02.2 Describe how the student should use the equipment in Figure 2 to compare the
power of the infrared radiation emitted by each surface.
[4 marks]
A student investigated how the power of the infrared radiation emitted from a flask
changed with time.
Table 1 shows the results.
Table 1
Time in seconds Power in watts
08.0
60 7.2
120 6.5
180 5.9
240 5.4
300 5.0
360 4.7
420 4.5
02.3 Describe the pattern shown by the data in Table 1.
[2 marks]
02.4 What is the most likely value for the power of the infrared radiation emitted
after 480 seconds?
Use Table 1.
[1 mark]
Tick ( ) one box.
4.0 W 4.2 W 7 4.4 W 4.6 W
A Leslie Cube is used to demonstrate that different surfaces emit different amounts of
infrared radiation.
Figure 3 shows an infrared detector and a Leslie Cube filled with hot water.
Figure 3
02.5 Give one advantage of using a Leslie Cube rather than the equipment in Figure 2 on
page 4.
[1 mark]
02.6 The teacher improved the demonstration by using four infrared detectors connected to
a data logger and computer. Each detector was pointed at a different surface of the
Leslie Cube.
The distance between the surface and the detector was the same in each case.
Give two reasons why this improved the demonstration.
[2 marks]
Mark scheme
Show the mark scheme
Question 2
AO /
Question Answers Extra information Mark
Spec. Ref.
02.1 any one from: 1 AO3
• stand up 6.6.2
• use a funnel
• pour water slowly
• pour at arms-length
• wear heat-proof gloves gloves on its own is insufficient
allow do not touch hot objects
(with bare hands)
AO /
Question Answers Mark
Spec. Ref.
02.2 Level 2: The method would lead to the production of a valid 3–4 AO1
outcome. All key steps are identified and logically sequenced. 6.6.2.2
Level 1: The method would not lead to a valid outcome. Some 1–2
relevant steps are identified, but links are not made clear.
No relevant content 0
Indicative content
• use the kettle to heat the water
• use measuring cylinder to measure volume of water
• same volume of water in each flask
• use the thermometer to measure temperature of the water
• ensure temperature is the same in each flask
• infrared detector the same distance from each flask
• use the infrared detector to measure the power of infrared
radiation from each flask and compare results
AO /
Spec. Ref.
02.3 as time increases the power 1 AO3
decreases 6.2.2
the change (in power) each 60s allow rate of decrease of power 1
decreases as the time increases decreases
AO /
Spec. Ref.
02.4 4.4 W 1 AO3
6.2.2
AO /
Spec. Ref.
02.5 any one from: 1 AO3
• all surfaces will be at the 6.2.2
same temperature
• temperature of the water does
not need to be measured
• more surfaces can be tested
• the procedure only needs to allow different surfaces can be
be done once tested at the same time
• volume of water does not
need to be measured
AO /
Spec. Ref.
02.6 measurements can be taken at allow no need to move the 1 AO3
the same time detectors / cube 6.2.2
results will be more accurate 1
Total Question 2 11
How to answer it
Investigating Infrared Radiation & Surfaces
What this question tests
This question assesses your ability to design a valid scientific investigation, identify control variables, and interpret non-linear data trends. It focuses on the emission of infrared radiation from different surfaces (Matt Black vs. Shiny White) and the advantages of using specialized equipment like a Leslie Cube and data loggers.
Safety First
Correct Answers
- Stand up while pouring.
- Use a funnel.
- Pour water slowly or at arm's length.
- Wear heat-proof gloves.
Common Errors
Simply writing "wear gloves" is not enough for the mark. You must specify heat-proof gloves. Also, "do not touch hot objects" is only accepted if you explain how (e.g., using tongs).
Writing a Valid Method
4 Marks - Levelled Response
Key Knowledge: Control Variables
To make this a fair test, you must keep everything the same except the surface colour:
- Volume of water: Use the measuring cylinder.
- Starting temperature: Use the thermometer.
- Distance: The infrared detector must be the same distance from each flask.
Exam Technique: The "Perfect" Method
Examiners look for a logical sequence. Use this 4-step structure:
- Setup: Use the kettle to heat water and the measuring cylinder to pour the same volume into both the matt black and shiny white flasks.
- Control: Use the thermometer to ensure the starting temperature is the same in both flasks.
- Measure: Place the infrared detector at a fixed distance from the first flask and record the power.
- Compare: Repeat for the second flask at the same distance and compare the two power readings.
Analyzing the Data
02.3: Describing the Pattern
There are two marks here, so you need two distinct points:
- Point 1: As time increases, the power emitted decreases.
- Point 2: The rate of decrease slows down over time (the curve gets flatter).
02.4: Predicting the Value
Look at the gaps in Table 1:
- 8.0 to 7.2 (Drop of 0.8)
- 7.2 to 6.5 (Drop of 0.7)
- 6.5 to 5.9 (Drop of 0.6)
- ...The drop is getting smaller by 0.1 each time.
- The last drop was 0.2 (4.7 to 4.5). The next drop should be 0.1.
- 4.5 - 0.1 = 4.4 W
The Leslie Cube & Data Loggers
Why use a Leslie Cube?
In the flask experiment, the two flasks might cool at different rates or start at slightly different temperatures. In a Leslie Cube:
- All four surfaces are at the exact same temperature because they are part of the same container of water.
- You only have to fill one container, making the procedure faster and more reliable.
02.6: Advantages of Data Loggers
When the teacher uses four detectors and a computer, it improves the experiment because:
- Simultaneous readings: All surfaces are measured at the exact same time.
- No Movement: You don't have to move the detector, which avoids changing the distance by accident.
- Accuracy: Data loggers reduce human error in reading scales and can take many more readings per second.
Common Error
Don't just say "it's faster" or "it's easier." Use scientific terms like accuracy, precision, or simultaneous measurements.
Summary Table: Infrared Emission
| Surface Type | Emission Quality | Absorption Quality |
|---|---|---|
| Matt Black | Best Emitter | Best Absorber |
| Shiny Silver/White | Worst Emitter | Worst Absorber (Best Reflector) |
Topics
Physics · P6: Waves · P1: Energy
Question and mark scheme from the AQA GCSE Combined Science: Trilogy examination, Physics Paper 2 (Foundation), 2022. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.