Different astronomical bodies have different gravitational field strengths at their surfaces, as detailed in the table below.
| Astronomical body | Surface gravitational field strength (N/kg\text{N/kg}N/kg) |
|---|---|
| Gliese 581g | 16.216.216.2 |
| Proxima Centauri b | 10.810.810.8 |
| Titan | 1.351.351.35 |
On which astronomical body's surface would an autonomous probe experience the greatest weight? Explain your answer.
State the primary physical characteristic of a planet or moon that determines its surface gravitational field strength.
On Earth, the autonomous probe has a weight of 2100 N2100 \text{ N}2100 N. The total contact area of its landing pads on the flat ground is 0.06 m20.06 \text{ m}^20.06 m2.
Calculate the pressure the probe exerts on the ground.
The probe is stationary on the ground. Describe the two vertical forces acting on the probe. In your answer, state their names, directions, and how their relative magnitudes compare.
39 exam-style questions on OCR GCSE Physics Forces in action. Each one has a worked solution and a mark scheme showing where the marks go.