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. |