A horizontal spring with a spring constant k = 322 N/m is uncompressed from a length of 1.4 cm back to its unstretched length. Calculate the change in potential energy in Joules to 2 s.f.

Answer 1

Lack of better data, assume the 1.4 cm is the difference between stretched and unstretched length.

Work done = Δpotential energy
= (1/2)k(Δx)²

First change everything to SI units then the result will be in joules.