Explain escape energy and give its definition.

Explanation

`implies` If we throw a stone upwards with our hand, it goes to a certain height and then falls back towards the earth
`implies` If it throw with larger speed it gets greater heights.
`implies` If a stone throw with such initial speed, it goes to infinite distance from earth gravitational field forever. In this position there is no attraction on it by the earth.
`implies` The thoughts of this situation is as below:
`implies` Suppose, a body is lying in the gravitational field of earth at a distance r from the centre of earth. This body is stationary, the total energy of this body ,
` E_i` = Kinetic energy + Potential energy
`E=0 +(-(GM_Em)/r)`
`E=-(GM_Em)/r" "...(1)`
`:. E = - (GM_(E)m)/(R_E+h) " "..(2)`
`implies` At infinite distance the total energy of body is considered as zero.
`implies` If energy `+ (GM_(E) m)/((R_(E) +h))` (or more this) is supply to body, its total energy becomes zero and the body will go to infinite distance it does not return in gravitational field of earth. This energy is known as escape energy.