An elastic spring of unstretched length L and spring constant K is stretched by a small length x. It is further stretched by another small length y. the work done in second stretcing is

Options

A. `1//2 Ky^(2)`
B. `1//2 Ky(2x+y)`
C. `1//2 K(x^(2)+y^(2))`
D. `1//2 k (x+y)^(2)`

Answer

B