Practice Questions 1.State the energy transfer that occurs when a spring is stretched or squashed.

Chemical potential energy is converted into elastic potential energy.

2. When is work done = elastic potential energy ?

During the linear part of a force-extension graph.

3. A spring has a spring constant  250 N/m and is stretched by $0.6m$. Calculate the elastic potential energy stored in the spring.

E_e = 1/2 x k x e²

E_e = 1/2 x 250N/m x 0.6²

Ee = 45J