(5) Two blocks of masses M and 4M are placed on a horizontal, frictionless surface. A light spring is attached to one of them, and the blocks are pushed together with the spring between them, as seen in the figure below. A cord initially holding the blocks together is burned; after this the block of mass 4M moves to the right (the positive direction) with a speed of V=2.07 m/s. M Before (a) M after (b) (5a) What is the velocity of the block of mass M? Submit Answer Tries 0/10 (5b) Calculate the original elastic energy in the spring if M Submit Answer Tries 0/10 = 0.305 kg. (6) A 2.84 kg sphere makes a perfectly inelastic collision with a second sphere that is initially at rest. The composite system moves with a speed equal to one fourth the original speed of the 2.84 kg sphere. What is the mass of the second sphere? Submit Answer Tries 0/10