question_answer

The kinetic energy needed to project a body of mass m from the earth's surface (radius R) to infinity is     [AIEEE 2002]

A)  \[\frac{mgR}{2}\]         

B)       2mgR

C)  mgR                

D)       \[\frac{mgR}{4}\]

Correct Answer: C

Solution :

[c] The minimum kinetic energy required to project a body of mass m from earth's surface to infinity is known as escape energy. Therefore,