1. The problem statement, all variables and given/known data A block of mass m = 2.80 kg slides down a 30.0° incline which is 3.60 m high. At the bottom, it strikes a block of mass M = 7.00 kg which is at rest on a horizontal surface, Fig. 7-41. (Assume a smooth transition at the bottom of the incline, an elastic collision, and ignore friction.) http://img141.imageshack.us/img141/4472/741ue2.gif [Broken] (a) Determine the speeds of the two blocks after the collision. Lighter Block: Heavier Block: (b) Determine how far back up the incline the smaller mass will go. 2. Relevant equations v=final velocity u= Initial velocity a=acceleration s= Displacement v^2=u^2+2as m1u1+m2u2=m1v1+m2v2 3. The attempt at a solution I resolved to find acceleration perpendicular to the plain of motion and also the displacement, but as i was not given an initial velocity i cannot find out the final velocity of the small block as it hits the large block Does any one have any ideas as to how i would go about solving this question?