Ok, here's the question: A 7.0 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 9.3 cm. Find the initial speed of the bullet. I'm using the formula: m1v1i + 0 = (m1 +m2)vf so i substitute in the info I'm given: .007v1i + 0 = 1.507kg(.002km/s) v1i = 0.43057 km/s, or 430.57 m/s but this is obviously not correct. Any suggestions?