The table below gives information about four hypothetical planets.
| Planet | Radius compared with the Earth | Average density (g/cm3\text{g/cm}^3g/cm3) | Surface gravity (m/s2\text{m/s}^2m/s2) |
|---|---|---|---|
| Anthe | 0.40 | 5.2 | 3.7 |
| Beid | 1.0 | 5.5 | 9.8 |
| Caelum | 3.8 | 1.3 | 11.2 |
| Draco | 11.2 | 1.3 | 24.8 |
Which statement about these planets is correct?
As the radius compared with the Earth increases, the average density increases.
As the radius compared with the Earth increases, the surface gravity increases.
As the average density increases, the surface gravity decreases.
The average density is directly proportional to the surface gravity.
100 exam-style questions on CIE IGCSE Physics 6.1 The Earth and the Solar System, covering 6.1.1a Rotation of the Earth, the seasons and the Moon, 6.1.1b Average orbital speed, 6.1.2a Contents of the Solar System, 6.1.2b Formation of the Solar System, 6.1.2c Gravitational field strength of a planet, and 6.1.2d Orbits and gravitational attraction. Each one has a worked solution and a mark scheme showing where the marks go.