Escape velocity from Earth's surface is 11.2 Kilometres/second.
How long would one need to maintain this escape velocity to actually escape Earth's gravitational pull? Must this 11.2 km/s velocity need to be maintained all the way up to geosynchronous orbit?
Best Answer
No, the escape velocity doesn't need to be maintained for any length of time. Escape velocity is the minimum speed you need to have at the Earth's surface to be able to escape the gravitational pull, without using a rocket or other continuous propulsion.
In other words, ignoring all sources of gravity other than the Earth, if you launch a projectile straight up at escape velocity from Earth's surface, it will slow down as it rises but will never quite stop. Any slower, and the projectile will stop at some point and fall back to Earth.