Gravitational potential

Need to know

What you need to know

• G is the Universal Gravitational Constant (6.67 x 10^-11 N m^2 kg^-2).
• M is the mass of the body creating the gravitational field (e.g., a planet).
• r is the distance from the centre of the mass M to the point in question.
• The negative sign is crucial: it signifies that the potential is defined as zero at infinity, and energy is released as a mass is brought closer.
• For a uniform spherical body, M can be treated as a point mass at its centre for any point outside the sphere.

Explanation

Gravitational potential

1. G is the Universal Gravitational Constant (6.67 x 10^-11 N m^2 kg^-2).
2. M is the mass of the body creating the gravitational field (e.g., a planet).
3. r is the distance from the centre of the mass M to the point in question.
4. The negative sign is crucial: it signifies that the potential is defined as zero at infinity, and energy is released as a mass is brought closer.