Physics In Flux. (Physics Blog)

Kepler's Second Law, The Law of Equal Areas: Kepler's second law of planetary motion states that "a line joining a planet and the Sun sweeps out equal areas in equal time intervals". This means that the planet moves faster when it is closer to the Sun and slower when it is farther away. To understand Kepler's second law, it is helpful to think about the concept of angular momentum. Angular momentum is the product of an object's mass, its velocity, and the distance from the object to the center of rotation. In the case of a planet orbiting the Sun, the angular momentum of the planet is constant. Kepler's second law of planetary motion. Angular momentum = Mass*Velocity*Distance from Sun to celestial body. L = MVR Now, angular momentum is constant (as angular momentum is conserved). Therefore, L and M are constant. R is a variable as the orbit is elliptical in shape (from the first law of Kepler). So, to compensate for the variable R, the velocity V of the pl