AQA GCSE Physics Physics Paper 2 (Higher), November 2020: Question 2
13 marks · Standard Demand difficulty · Extended Answer
Answer questions about the Sun, star stability, speed-distance-time calculations, life cycle of massive stars, and black body radiation wavelengths.
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Question text
02.1 Complete the sentences.
[2 marks]
The Sun is a stable star. This is because the forces pulling inwards caused by
are in equilibrium with the forces pushing outwards caused
by the energy released by nuclear .
02.2 Write down the equation that links distance travelled (s), speed (v) and time (t).
[1 mark]
02.3 The mean distance between the Sun and the Earth is 1.5 × 1011 m.
Light travels at a speed of 3.0 × 108 m/s.
Calculate the time taken for light from the Sun to reach the Earth.
[3 marks]
Time = s
02.4 Some stars are much more massive than the Sun.
Describe the life cycle of stars much more massive than the Sun, including the
formation of new elements.
[6 marks]
02.5 Stars emit radiation with a range of wavelengths.
Which property of a star does the range of wavelengths depend on?
[1 mark]
Tick ( ) one box.
Density
Mass
Temperature
Volume
Mark scheme
Show the mark scheme
Question 2
AO /
Question Answers Extra information Mark
Spec. Ref.
02.1 (force of) gravity do not allow weight 1 AO1
4.8.1.1
fusion 1
02.2 distance = speed × time allow a correct re-arrangement 1 AO1
4.5.6.1.2
or
s = vt do not allow d = st
02.3 1.5 × 1011 = 3.0 × 108 × t 1 AO2
4.5.6.1.2
1.5 × 1011 1
t = 8
3.0 × 10
t = 500 (s) 1
Level 3: Scientifically relevant facts, events or processes are AO1
02.4 5–6
identified and given in detail to form an accurate account. 4.8.1.2 9
Level 2: Scientifically relevant facts, events or processes are
identified and their relevance is clear. The account is not fully 3–4
accurate.
Level 1: Facts, events or processes are identified and simply
1–2
stated but their relevance is not clear.
No relevant content 0
Indicative content:
• fusion (processes in stars) produce new elements
• cloud of gas / hydrogen and dust OR nebula
• pulled together by gravity
• causing increasing temperature (to start the fusion process)
• (to become a) protostar
• hydrogen nuclei fuse to form helium nuclei
• and the star becomes main sequence
• hydrogen begins to run out
• helium nuclei fuse to make heavier elements
• up to iron
• the star expands (to become a)
• red super giant
• (the star collapses rapidly) and explodes
• called a supernova
• creating elements heavier than iron
• and distributing them throughout the universe
• leaving behind a neutron star
• or a black hole.
02.5 Temperature 1 AO1
4.6.3.2
Total 13
How to answer it
GCSE Physics Study Guide: Space Physics & Motion
What this question tests
This exam question assesses your knowledge of stellar evolution (life cycle of stars), gravitational equilibrium in stable stars, standard wave/speed calculations linking distance, speed, and time, nuclear fusion processes, and the relationship between a star's temperature and the electromagnetic radiation it emits.
Equilibrium in the Sun
✅ Correct Answers
- Gap 1: gravity (or force of gravity)
- Gap 2: fusion (or nuclear fusion)
💡 Key Knowledge
- A stable star is in a delicate balance called equilibrium.
- Inward gravitational forces try to collapse the star, while outward thermal/radiation pressure from nuclear fusion pushes it apart.
❌ Common Errors
Writing "weight" instead of "gravity". The mark scheme explicitly forbids "weight" because weight is a force experienced *on* an object due to a gravitational field, whereas stars exert a mutual gravitational pull.
Linking Distance, Speed, and Time
✅ Correct Answers
- distance = speed × time
- s = v × t (or any valid algebraic rearrangement)
❌ Common Errors
Writing standard shorthand like d = st is not accepted by AQA for this specific equation; you must use s = vt or write it out in words.
Time Taken for Sunlight to Reach Earth
📐 Step-by-Step Calculation
- State the formula: s = v × t or t = s / v
- Substitute values: 1.5 × 10¹¹ = 3.0 × 10⁸ × t
- Rearrange & solve: t = (1.5 × 10¹¹) / (3.0 × 10⁸)
- Final Answer: 500 s
🧠 Exam Technique
Always show your substitution clearly, even if you are using standard form numbers. This secures method marks even if your calculator entry slips up.
Life Cycle of Massive Stars & Element Formation
💡 Indicative Content (The Journey)
- Nebula: Dust and hydrogen gas pulled together by gravity.
- Protostar: Temperature rises as particles collide, initiating nuclear fusion.
- Main Sequence: Hydrogen nuclei fuse to form helium nuclei (long stable period).
- Red Super Giant: Hydrogen runs out; heavier elements up to iron are fused.
- Supernova: The star collapses rapidly and explodes.
- Remnants: Distributes elements throughout the universe, leaving behind a neutron star or a black hole.
🧠 Level of Response Strategy
Level 3 (5–6 marks): A detailed, logically structured account covering both the life cycle stages *and* how new elements are formed through fusion and supernova explosions. Avoid chronological gaps!
Wavelengths of Radiation Emitted by Stars
✅ Correct Answer
Tick: Temperature
💡 Key Knowledge
The distribution of wavelengths (the continuous spectrum of radiation) emitted by a star depends directly on its surface temperature. Hotter stars emit a higher proportion of shorter wavelengths (like UV and blue light).
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), November 2020. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.