A 0.3-kg block is held in place against the spring by a 60-N horizontal external force. The external force is removed, and the block is projected with a velocity v1= 1.2 m/s when it is separated from the spring, as shown in the figure. The block descends a ramp and has a velocity v2=1.4 m/s at the bottom of the ramp. 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 between the block and the rough surface is 0.26. The block advances to D, where it stops. By how many centimeters was the spring initially compressed?

2 VI Smooth B C D E Rough