Gravitational methods

Abstract

Newton’s law of gravitation states that the force (in newton) between two point masses m₁, m₂ is equal to Gm₁ m₂/r² where ris the distance between the masses and G = 6.670 × 10⁻¹¹ [≈(20/3) × 10⁻¹¹] m³ /kg s². A unit mass placed in the vicinity of any body will be in a field of force (gravitational field) and experience an acceleration. The force may be calculated by applying Newton’s law to infinitesimal volume elements of the body and integrating over the entire volume. The earth has also a gravitational field but in calculating it account must be taken of the centrifugal force due to the rotation of the earth.