Explain why the gravitational field strength on the surface of Jupiter is greater than the gravitational field strength on the surface of the Earth.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Jupiter has a much greater mass than the Earth. Jupiter also has a much larger radius than the Earth.
Model answer (5 marks)
The gravitational field strength g at a planet’s surface is given by g=GM/r², where M is the planet’s mass and r its radius.
1. Jupiter’s mass (M_J) is far greater than Earth’s mass (M_E).
2. A larger M increases g proportionally.
3. Jupiter’s radius (r_J) is also larger than Earth’s radius (r_E).
4. A larger r would reduce g (since g∝1/r²).
5. However, the increase in M is much larger than the increase in r, so the net effect is that g_J>g_E.
Therefore, the gravitational field strength on Jupiter’s surface is greater than that on Earth’s surface.
1. Jupiter’s mass (M_J) is far greater than Earth’s mass (M_E).
2. A larger M increases g proportionally.
3. Jupiter’s radius (r_J) is also larger than Earth’s radius (r_E).
4. A larger r would reduce g (since g∝1/r²).
5. However, the increase in M is much larger than the increase in r, so the net effect is that g_J>g_E.
Therefore, the gravitational field strength on Jupiter’s surface is greater than that on Earth’s surface.
Examiner tips
- Use the formula g=GM/r² to show the dependence on M and r; mention the proportionality explicitly.
- Explain the competing effects of mass and radius and state that the mass effect dominates.
- Show the comparison of Jupiter’s and Earth’s values qualitatively; no need for exact numbers.
Mark scheme (5 marks)
- Gravitational field strength depends on the mass of the object producing the field
- Jupiter has a much greater mass than the Earth
- Greater mass means a stronger/larger gravitational field strength (so this acts to increase g on Jupiter)
- Gravitational field strength also depends on the distance from the centre of the planet / the radius
- Despite Jupiter's larger radius (which would reduce field strength), the effect of Jupiter's much greater mass is dominant, so the overall gravitational field strength at its surface is greater than Earth's
Key terms in this question
Related
- All AQA A-Level Physics (7408) revision notes →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →
More Gravitational Fields questions
- Explain why the gravitational field strength decreases as a spacecraft travels a…
- A student states: 'The gravitational field around the Earth is uniform everywher…
- Explain why an astronaut's weight changes when they travel from the surface of t…
- Explain why the gravitational field strength at the surface of the Moon is less …