Escape Velocity

For an object to be thrown from the surface of a planet and escape the gravitational field (to infinity) the initial kinetic energy it has at the surface must be equal to the potential energy (work done) to take it from the surface to infinity.

Potential energy: Kinetic energy:

For an object to be escape the Earth…..

v = 11183 m/s

This calculation is unrealistic. It assumes that all the kinetic energy must be provided instantaneously. We have multistage rockets that provide a continuous thrust.