Which is an example of kinetic energy?

a. a ball sitting at the top of a ramp

b. the energy stored in ethanol

c. a compressed spring

d. a hockey puck sliding across the ice

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.