- 2

- 1

- Homework Statement
- A block of mass "m" kept on a fixed ground is connected to a spring. The spring is currently in it natural length "L". We mark a point "P" on the spring at height "0.8L". The block is of negligible height. An external force is acting on the spring such that it's acceleration is zero and after some time the point "P" reaches height "L" Find the Work done by the External Force.

- Homework Equations
- None

I have tried using Conservation of Energy but I'm getting incorrect answer.