| Force
A force is a push, pull or twist that can be exerted on a body or object. A force is a vector quantity, requiring magnitude, direction and a point of application for its description. F = ma Centripetal Acceleration a = v ² / r a = 4 p ² r / t ² a = G M / d ² Centripetal Force F = m * v ² / r F = m 4p ² r / t ² F = G Mm / d ² Gravitational Constant G = 6.67 * 10 -11 Minimum Orbit Velocity vmin = Ö (gr) Kepler's Laws 1. Planets and orbiting bodies move in elliptical paths with the sun being at one focus 2. The area swept out in a given time by the radius vector is always constant (diagram???) 3. For orbiting satellites (or planets) of any system, the ration (radius of orbit) ³ / (period) ² is constant for all satellites of that system. |