physics demo of conservation of momentum

what you see is my physics prof lying on a bed of nails. he has a piece of plywood placed over his chest. on the plywood is an anvil. on the anvil is a concrete cinder block. the gentleman placing the cinder block is about to swing a sledge hammer and break this block. the demo provided us with memorable proof that during inelastic collisions, momentum from a less massive object is dispersed if that object impacts a more massive object.