Here's the situation: A small block of wood of inertia mb is released from rest a distance h above the ground, directly above your head. You decide to shoot it with your pellet gun, which fires a pellet of inertia mp. After the block has fallen a distance d, the pellet hits it and becomes embedded in it, kicking it upward. At the instant of impact, the pellet is moving at speed vp. I'm supposed to find the maximum height formula, and this is what I got but it's incorrect: http://imgur.com/gallery/QQoFRm7 *Relevant equations* : x = vt + 1/2at^2 v = at p = mv vf^2=vi^2+2ad Can someone help me on this? What I did was 1) found the velocity of the block after falling distance d, 2) found the velocity of the block + pellet after collision by viewing it as a completely inelastic collision, 3) plugged it into the vf^2 = vi^2+2ad, 4) added (h-d). Does anyone see where I'm going wrong? I have 2 more tries until I don't get any credit for it. I know this is a long problem so much thanks if anyone can point me in the right direction.