1.
A block of mass m=0.1m = 0.1 kg is connected to a spring of unknown spring constant kk. It is compressed to a distance from its equilibrium position and released from rest. After approaching half the distance (x/2)(x/2) from the equilibrium position, it hits another block and comes to rest momentarily, while the other block moves with velocity 3 m/s. The total initial energy of the spring is: