A. (20pts) A m = 7.0-kg block on a horizontal surface is attached to light spring (force constant k = 1.2 kN/m). The block is initially at rest at its equilibrium position when a force of magnitude F acting parallel to the surface is applied to the block during t = 6.0 s, as shown. When the block is L = 8.0 cm from the equilibrium position, it has a speed of v = 0.80 m/s. The coefficient of kinetic friction, uk, between the block and the horizontal surface is 0.20. Use only energy methods to solve this problem. F ..... (a) How much work is done on the block by the force F as the block moves the L = 8.0 cm? (8 pts) (a) How much work is done on the block (c) What is the average power produced by the force F as the block moves the L = 8.0 cm in t = 6.0 s? (5pts)