A block A of mass `2 kg` is moving to right with a speed of 5 m/s on a horizontal smooth surface. Another block B of mass 2 kg, with a mass less spring of force constant `K =200` N/m attached to it, is moving to left on the same surface with a speed of 3 m/s. Block A collides with the spring attached to B. Calculate
(a) the final velocity of the block A.
(b) the minimum kinetic energy of the system of two blocks during subsequent motion.
(c) Repeat part (b) if there is no spring and the two blocks collide head on. Assume that the blocks are made of perfectly elastic material