If an object of mass m is taken from the surface of earth to a height 2R, then the word done is

Options

A. a)2mgR
B. b)mgR
C. c)`2/3 mgR`
D. d)`3/2 mgR`

Answer

C

Explanation

Work done
`W= Delta U= (mgh)/ (1+h/R)`
Substituting h=2R, we get
`Delta U= (mg2R)/(1+2)`
`Delta U= (2mgR)/3`