A body is projected vertically upwards from the surface of the earth with a velocity equal to half of escape velocity of the earth. If `R` is radius of the earth, maximum height attained by the body from the surface of the earth is

Options

A. `R//6`
B. `R//3`
C. `2R//3`
D. `R`

Answer

B

Explanation

Maximum height attained by body
`h=R[(v^(2))/(v_(e)^(2)-v^(2))]rArr h=R[(v_(e)^(2)//4)/(v_(e)^(2)-v_(e)^(2)//4)]=R[(v_(e)^(2)//4)/(3_(e)^(2)//4)]rArrh=(R)/(3)`.