Need help with this Work and energy problem

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.

because if the tool that you are using is not balanced it there would be false mass.

the right answer is 0.3 meters per second

answer///scientific method;