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- Aug 7, 2001
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Let's keep it simple: gravitational energy is NOT infinite. If a body falls from infinity to Earth, it accelerates all the time until impact. It then has a particular speed (NOT infinite) which is a measure of its energy.
Conversely, if a body on the surface of the Earth is accelerated to this velocity, it will have sufficient energy to escape Earth's gravity and travel infinitely far into space - thus this speed is called Escape Velocity.
(Escape Velocity depends on the mass and radius of the gravitating body - it's proportional to the square root of mass divided by radius.)
Conversely, if a body on the surface of the Earth is accelerated to this velocity, it will have sufficient energy to escape Earth's gravity and travel infinitely far into space - thus this speed is called Escape Velocity.
(Escape Velocity depends on the mass and radius of the gravitating body - it's proportional to the square root of mass divided by radius.)