The potential energy of a certain spring when stretched through a distance 'S' is `10` joule. The amount of work (in joule) that must be done on this spring to stretch it through an additional distance 'S' will be

Options

A. `30`
B. `40`
C. `10`
D. `20`

Explanation

`U = (1)/(2) ks^(2) = 10 J` (i)
`U' = (1)/(2) k(s + s)^(2) = 4 ((1)/(2) Ks^(2)) = 40 J` (ii)
`W = U' - U = 40 - 10 = 30 J`