UNIT 07 - GRAVITY & KEPLER'S LAWS

Orbits of Planets and Satellites
A) Students should understand the motion of an object in orbit under the influence of gravitational forces, so they can:
 (1) Recognize that the motion does not depend on the object’s mass; describe qualitatively how the velocity, period of revolution, and centripetal acceleration depend upon the radius of the orbit; and derive expressions for the velocity and period of revolution in such an orbit.
(2) Derive Kepler’s Third Law for the case of circular orbits.
(3) Derive and apply the relations among kinetic energy, potential energy, and total energy for such an orbit.
(4) State Kepler’s three laws of planetary motion and use them to describe in qualitative terms the motion of an object in an elliptical orbit.
(5) Apply conservation of angular momentum to determine the velocity and radial distance at any point in the orbit.
(6) Apply angular momentum conservation and energy conservation to relate the speeds of an object at the two extremes of an elliptical orbit.
(7) Apply energy conservation in analyzing the motion of an object that is projected straight up from a planet’s surface or that is projected directly toward the planet from far above the surface.