D.1.8 Gravitational Equipotential Surfaces – Check yourself

Equipotentials of an isolated spherical planet are

Work done in moving a mass between two points on the same equipotential is

Equipotentials spaced for equal ΔV become more widely spaced at larger distance because

Near the Earth's surface over a small region, the equipotentials are

The potential at the surface of a planet is −4.0 × 10⁷ J kg⁻¹. The equipotential surface with V = −2.0 × 10⁷ J kg⁻¹ is at a distance from the centre of