Two blocks of masses M and 3M areplace on a horizontal, frictionless surface. A light spring isattached to one of them, and the blocks are push together with thespring between them (Fig. above). A cord initially holding theblocks together is burned; after this, the block of mass 3M movesto the right with a speed of 2.00m/s (a) what tis the speed of theblock of mass M? (b) Find the original elastic potential energy inthe spring if M = 0.350 kg
