A marble is dropped from 2.5 m and hits the ground in 0.71 s. What is the final velocity before it hits the ground?

pe = weightxheight = 2000x1000=2,000,000joules

probably not if net force is zero

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.