The speed of a nerve impulse in the human body is about 100 m/s. if you accidentally stub your toe in the dark, estimate the time it takes the nerve impulse to travel to your brain.

problem is worked out down below in an attachment

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.