An object of mass 20 kg changes velocity from 20 m/s to 60 m's over 10 seconds with a constant acceleration. Find the force that is causing this to happen (hint: what are you
missing froin the force equation? can you find it with the data given?)

the answer is b, have negligible mass

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.

you get 2.3=1.21*\frac{a}2 or 4.6=1.21a or a=3.802 (b)

explanation: