In the classroom demonstration where a volunteer strikes an anvil resting on the physics professor's chest will he lies reclined, the anvil shields the daring physics professor from most of the sledgehammer's:
a) momentum
b) kinetic energy

neither
explain!

the skeletons of most mammals reach a certain size and then stop growing. however, many animals, including some mammals, keep growing throughout their lives. kangaroos, for example, just keep growing and growing until they die. also, the longer an animal lives the greater the chance it might catch some deadly disease.