Elastic and Inelastic Collisions of a Ball with a Wood Block

In a recent article in this journal, Shakur described an interesting problem where a bullet of mass m strikes a block of wood of mass M and projects the block upward. The same problem was considered earlier by Cowley et al. and others. The main question of interest is whether the block rises to a greater height if it is struck in the middle rather than near one end. Conservation of energy or conservation of momentum arguments, on their own, appear to yield very different predictions. Both Shakur and Cowley et al. indicated that the block would rise to the same height, regardless of the impact point, based simply on a conservation of momentum argument.