Question

The escape velocity of a body on a planet is always _______ the orbital velocity of the body around the planet in an orbit closer to it.

• A. greater than
• B. less than
• C. equal to
• D. None

Answer 1

The correct option is A greater than

Escape velocity is how fast you have to go to leave earth's atmosphere.
Orbital speed is how fast something needs to travel to maintain orbit.
Escape velocity is the speed that you need to leave the planet so that without any more push you keep moving away forever. Orbital speed is the speed needed to circle the planet at the same altitude without getting farther or closer. From any circular orbit you need to speed up by a factor of the $\sqrt{2}$ to get to escape velocity. For Low Earth orbit, orbital speed is 17,500 MPH, and escape velocity is $\sqrt{2}$ (about 1.414) times as fast, or a little less than 25,000 MPH.