the original problem: A 0.010-kg bullet traveling horizontally at 400.0 m/s strikes a 4.0-kg block of wood sitting at the edge of a table. The bullet is lodged into the wood. If the table height is 1.2 m, how far from the table does the block hit the floor? this is what i did: lets the mass of bullet = m2 the mass of block of wood = m1 velocity of the block of wood before the collision take place = v1 velocity of the bullet = v2 velocity of the block and bullet after the collision take place = vf momenta of the block = p1 momenta of the bullet = p2 the momentum of block and bullet after collision equals the sum of momenta of the block and the bullet before the collision: pf = pi The initial momentum is the sum of the momenta of the block and bullet pf = p1 + p2 Since the block is initially at rest, p1 = 0. Then pf = p2 or (m1 + m2)(vf) = (m2)(v2) Solving for vf: vf = [(0.010)(400.0)]/(4.0+0.010) = 0.9975 m/s And I stuck here because I didn't know how to calculate the distance from the table to the point that the block hit the floor. Am I have to use the projectile motion concept? Your help would be highly appreciate.