Question

Expression for Escape Velocity.

Answer 1

The initial velocity with which an object escapes the earth's gravitational force is called as escape velocity.

escape velocity =
$\sqrt{2gr}$

Answer 2

Expression for escape velocity:-

Let a body of mass m be escaped from the gravitational field of the earth.

During the course of motion, let at any instant, body be at a distance r from the center of the earth.

The gravitational force between body and the earth is,

F= GM / r² dr_

Work done to raise the body by distance dr is,

dw = GMm / r² dr_

Total work done, w in raising the body from the surface of the earth to infinity is,

After this see the attachment...