1. The problem statement, all variables and given/known data A 7.00g bullet, when ired from a gun into a 1.00kg block of wood held in a vise, penetrates the block to a depth of 8.00cm. This block of wood is placed on a frictionless horizontal surface, and a second 7.00g bullet is fired from the gun into the block. To what depth will the bullet penetrate the block in this case? 2. Relevant equations 3. The attempt at a solution In the first case, by taking the final velocity as 0 and displacement as 8.00cm. I can get the initial velocity of bullet in terms of acceleration or time by using kinematics equations. or I can find the force of the bullet exerts on the block by equating EK = F[tex]\Delta[/tex]r But they are not seems to be useful in case 2. In case 2, I am not sure how the mechanics will occur. But, I think the bullet will travel with the same initial velocity, penetrate a shorter distance into the block and bring the block to travel with it with some velocity. I do not know how to put this by using physical principals. I guess I need to use conservation of energy again. By equating EK of bullet = F[tex]\Delta[/tex]r + EK of (bullet + block). But I do not think I have enough information to do that. Please help me.