Escape velocity of a body `1 kg` mass on a planet is `100 ms^(-1)`. Gravitational potential energy of the body at that planet is

Options

A. 5000J
B. `-5000J`
C. `-2400J`
D. `-1000J`

Answer

B

Explanation

Escape velocity `(v_(e ))=sqrt((2GM)/(R )) " " therefore v_(e )^(2)=(2GM)/(R )`
`therefore (GM)/(R )=(v_(e )^(2))/(2)" "` ……(1)
and gravitational P.E. (U) `=-((GM)/(R ))m`
`=-((v_(e)^(2))/(2))m " "` …. From (1)
`therefore U=-((100xx100)/(2)xx1)=-5000 J`