Define escape energy?

Answer 1

I think you mean escape velocity.

Escape velocity is the speed required for any object with mass such as a spacecraft to be able to get free of the earth's (or another planet or celestial body) gravitational field. Any high altitude object travelling at less than the escape velocity will always fall back to earth. Escape velocity is proportional to the mass of the planet - the higher the mass of the planet, the higher the escape velocity. F=MV, and the object needs enough force or energy to escape the earth's gravitational field.

Here are the escape velocities for some common bodies in our solar system:

Earth: 11.2 km/sec
Moon: 2.4
Mercury: 4.3
Venus: 10.3
Mars: 5.0
Jupiter: 37.0
Sun: 618

Answer 2

Escape energy is the sum of potential energy and kinetic energy for an object whose trajectory just barely gets it out of the gravity well that it's in.

This is a more useful parameter than escape velocity because the escape velocity is constantly changing, while the escape energy is constant.

If your trajectory doesn't get you out of the gravity well, you can subtract your present energy from escape energy to see how much energy you must acquire in order to escape.

Answer 3

The amount of energy required to propel an object to escape velocity and escape the Earth's gravitation force?