A block of mass 0.500 kg is pushed against a horizontal spring of negligible mass until the spring is compressed a distance x as in figure. The force constant of the spring is 450 N/m. When it is released, the block travels along a frictionless, horizontal surface to point B, the bottom of a circular track of R = 1.00 m, and continues to move along the track. The speed of the block at the bottom of the track is v_s = 12.0 m/s, and the block experience an average friction force of 7.00 N while sliding up the track. (a) What is x? (b) What speed do you predict for the block at the top of the track? (c) Does the block actually reach the top of the track, or does it fall off before reaching the top?