1. The problem statement, all variables and given/known data Consider a bullet of mass m fired at a speed of Vo into a wooden block of mass M. The bullet instantaneously comes to a rest in the block. The block with the embedded bullet slides along a horizontal surface with a coefficient of kinetic energy U. How far (s) does the block slide before it comes to rest. Express your answer in terms of m,M,Vo,U and g. 2. Relevant equations None given 3. The attempt at a solution (m+M)Vf=mVo thus Vo=(m+M)/m*Vf and Vf=root of (2gs) So (Vo*m/m+M)^2 = 2gs s=(1/2g)(Vo*m/m+M)^2 Now my question is if this is correct. I know this is the equation used when the wood is on a pendulim. Where is the U that they give?