physics help?

Question

A block of mass m = 600 g is released from rest and slides down a frictionless track of height h = 62.5 cm. At the bottom of the track the block slides freely along a horizontal table until it hits a spring attached to a heavy, immovable wall. The spring compressed by 2.81 cm at the maximum compression. What is the value of the spring constant k?

Answer 1

2*m*g*h = k*x^2

k = 2*0.6*9.806*0.625/0.0281^2 = 9,310 N/m