A 0.54 kg block is held in place against the spring by a 65-N horizontal external force. The external force is removed, and the block is projected with a velocity v1 = 1.2 m/s upon
-separation from the spring. The block descends a ramp and has a velocity v2 = 1.4 m/s at the
bottom. The track is frictionless between points A and B. The block enters a rough section at
B, extending to E. The coefficient of kinetic friction is 0.36. The velocity of the block is
v3 = 1.4 m/s at C. The block moves on to D, where it stops. In Fig. 7.4, the initial compression
of the spring, in cm, is closest to: Hint: use hooke's law and substitute k into the spring
energy equation.