Question

The work done in stretching a spring of force constant k from length $l_{1}\ and\ l_{2}$ is(a) $k(l_{2}^{2}-l_{1}^{2})$(b) $\frac{1}{2}k(l_{2}^{2}-l_{1}^{2})$(c) $k(l_{2}-l_{1})$(d) $\frac{k}{2}(l_{2}+l_{1})$

Answer 1

this question is impossible to solve