(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 v1=2.07 m/s. (5a) What is the velocity of the block of mass M? :] [M Tries 0/10 (5b) Calculate the original elastic energy in the spring if M = 0.305 kg. Submit Answer Tries 0/10 '0 a (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? SubmitAnswer Tries O/ 10