A block of mass 0.540 kilogram is pushed against a horizontal spring of negligible mass until the spring is compressed a distance x. 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 vertical circular track of radius R = 1.00 meter, and continues to move up the track. The speed of the block at the bottom of the track is vB = 12.1 m/s, and the block experiences an average frictional force of 7.00 Newton while sliding up the track.
(a) Find what is x?
m
(b) Find what speed do you predict for the block at the top of the track?
m/s