1. The problem statement, all variables and given/known data https://aapt.org/physicsteam/2010/upload/2009_F-ma.pdf See # 14 2. Relevant equations None really, perhaps keep in mind that 1) p is conserved in the absence of external forces 2) L is conserved in the absence of external torque 3) Mech E is conserved if no energy is lost due to external forces 3. The attempt at a solution I'm not sure how to attack this problem. My reasoning was that the bullet, as it is embedded into the block, has most of its velocity absorbed by the interior of the block (not rigorous at all). This means that the block does not move at the velocity it should and thus all A, B, C, D are false. How can I do this rigorously?