Help needed with physics

Question

A 1200 kg safe is 2.4 m above a spring when the rope holding the safe breaks. The safe hits the spring and compresses it 42 cm. What is the spring constant of the spring?

Answer 1

The Potential energy of the safe 2.4 m above the spring =1200*2.4*g and the spring must absorb all of that energy to stop it's fall and that = 1/2kx². Setting to the two equal to each other yield k = 320326 N/m.