PLEASE HELP A 0.25 kg ball strikes a 1.25 kg ball at rest. after collision the 0.25 kg ball is moving with a velocity of 18 m/s, and the second ball is moving with a velocity if 9m/s .what is the initial velocity of the first ball?

b

explanation:

i am pretty sure it is c because when people are closer together, they cannot move as freely. picture being in a mostly full elevator, for instance. the people are right next to you, and you can barely move.

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.