1. The problem statement, all variables and given/known data A 7-g bullet is fired into a 1.5-kg ballistic pendulum. The bullet emerges from the block with a speed of 200 m/s, and the block rises to a maximum height of 12 cm. Find the initial speed of the bullet. 2. Relevant equations conservation of momentum 3. The attempt at a solution First I tried to find the initial momentum of the bullet as if it did't penetrate the block so .007vi = (1.507)vf because I have two unknowns I used the conservation of mechanical energy to solve for vf 1/2(1.507)(vf2) = (1.507)(9.8)(.12) vf = 1.54 m/s then plug that in to find the initial velocity vi = 435.29 m/s initial momentum = 3.05 Then I tried to find the momentum of the bullet exiting the block and add it to the initial momentum to get the total initial momentum. 200(.007) = 1.4 1.4 + 3.05 = 4.45 and finally I divided that by the mass to get the initial velocity 635.75 m/s. The correct answer is 529 m/s.