AQA GCSE Physics Physics Paper 2 (Higher), June 2023: Question 6
12 marks · Standard Demand difficulty · Extended Answer
Calculate the frequency of microwaves used by the Hubble Space Telescope, explain the effect of Earth's gravitational force on its motion, and analyze visible light spectra for galaxies to determine red-shift and motion.
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Question text
06 Figure 15 shows the Hubble Space Telescope orbiting the Earth.
Figure 15
06.1 What name is given to objects that orbit a planet?
[1 mark]
06.2 A space telescope uses microwaves to communicate with the Earth.
A microwave has a wavelength of 12.5 cm.
The speed of microwaves through space is 3.0 × 108 m/s.
Calculate the frequency of the microwave.
Use the Physics Equations Sheet.
Give your answer in standard form.
[5 marks]
Frequency (in standard form) = Hz
06.3 Explain the effect of the Earth’s gravitational force on the motion of the
Hubble Space Telescope.
[3 marks]
06.4 The Hubble Space Telescope can detect visible light from distant galaxies.
The visible light spectra from stars and galaxies include dark lines
at specific wavelengths.
Figure 16 shows the visible light spectra from the Sun and two galaxies.
Figure 16
Explain what conclusions can be made about galaxies A and B.
[3 marks]
Mark scheme
Show the mark scheme
Question 6
AO /
Question Answers Extra information Mark
Spec. Ref.
06.1 satellite allow moon 1 AO1
4.8.1.3
AO /
Spec. Ref.
06.2 12.5 cm = 0.125 m 1 AO2
4.6.1.2
3 × 108 = f × 0.125 this mark may be awarded for 1
an incorrectly / not converted
value for wavelength
3 × 108
this mark may be awarded for 1
f =
0.125 an incorrectly / not converted
value for wavelength
this mark may be awarded for 1
f = 2 400 000 000 (Hz) an incorrectly / not converted
value for wavelength
this mark may be awarded for 1
f = 2.4 × 109 (Hz)
an incorrectly calculated value
for frequency in standard form
using the given data
AO /
Spec. Ref.
06.3 gravitational force causes the 1 AO1
Hubble Space Telescope to 4.5.1.1
accelerate towards the Earth 4.5.6.1.3
4.8.1.3
this changes the direction of 1
motion (but not the speed)
so changes the velocity of the 1
Hubble Space Telescope if no other marks awarded, allow
1 mark for gravitational force
maintains circular orbit–HYSICS – –
AO /
Spec. Ref.19
06.4 galaxy A has the greater red 1 AO3
shift 4.8.2
(so) A is travelling (away from 1
us) faster (than B)
(because) A is further away 1
(from us than B)
if no other marks awarded, allow
1 mark for galaxy A and galaxy
B are moving away from us
Total Question 6 12
How to answer it
Space Physics & Waves Exam Guide
What this question tests
This question assesses your knowledge of Space Physics and Waves. You will be tested on orbital motion, applying the wave equation with unit conversions, standard form calculations, and interpreting light spectra to explain red-shift and the expansion of the universe.
Naming Orbiting Objects
✅ Correct Answer
Satellite (allow "moon")
💡 Key Knowledge
A satellite is any object that orbits a larger body. Natural satellites include moons and planets, while artificial satellites are man-made objects like the Hubble Space Telescope or the International Space Station.
Wave Equation & Standard Form Calculation
📐 Step-by-Step Calculation
- Convert units: Wavelength must be in metres. 12.5 cm ÷ 100 = 0.125 m
- State the wave equation: speed = frequency × wavelength (or v = f × lambda )
- Rearrange for frequency: f = speed / wavelength
- Substitute values: f = (3.0 × 10⁸) / 0.125
- Calculate standard form: 2 400 000 000 Hz = 2.4 × 10⁹ Hz
❌ Common Errors & Traps
- Forgetting to convert units: Using 12.5 directly instead of converting to metres ( 0.125 m ) leads to completely wrong values.
- Standard Form formatting: Failing to convert the final large number into standard form format ( A × 10ⁿ where 1 ≤ A < 10 ).
Gravitational Force and Orbital Motion
✅ Correct Answer
To score full marks, explain that:
- Gravitational force causes the telescope to accelerate towards the Earth.
- This force changes its direction of motion (perpendicular to its velocity), but not its speed.
- Therefore, it continuously changes the velocity of the telescope, maintaining its circular orbit.
🧠 Exam Technique
In physics, velocity is a vector (speed + direction). Even though the telescope maintains a constant speed, because its direction is constantly changing due to gravity, its velocity is constantly changing. Mentioning acceleration towards the centre is crucial.
Red-Shift and Spectra Analysis
✅ Correct Answer
- Galaxy A has the greater red-shift (spectral lines are shifted further towards the red/longer wavelength end compared to the Sun and Galaxy B).
- Therefore, Galaxy A is travelling away from us faster than Galaxy B.
- This is because Galaxy A is further away from us than Galaxy B (correlating distance with speed via Hubble's Law).
💡 Key Knowledge & Red-Shift
When light from distant galaxies moves away from us, the wavelength increases (shifted towards the red end of the spectrum). Greater red-shift means a higher speed of recession, which implies a greater distance from Earth.
Topics
Physics · P5: Forces · P6: Waves · P8: Space Physics (physics only)
Question and mark scheme from the AQA GCSE Physics examination, Physics Paper 2 (Higher), June 2023. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.