A block whose mass is 1 kg is fastened to a spring. The spring has...

A block whose mass is 1 kg is fastened to a spring. The spring has a spring constant of 50 N m–1. The block is pulled to a distance x = 10 cm from its equilibrium position at x = 0 on a frictionless surface from rest at t = 0. Calculate the potential energy of the block when it is 5 cm away from the mean position.