Question

A spring has a spring constant of 80 N/m. How much energy is stored in the spring when it is compressed 0.2 m past its natural length?

Answer 1

The energy of a compressed (or stretched) spring is given by

$E= \frac{1}{2} k x^{2}$

This gives

$E= \frac{1}{2}80* 0.2^{2} =1.6J$