Consider the motion of the balloon and its air contents in terms of momentum. In step 1 above, the total momentum of the balloon and its contents was zero. Recall that momentum = mv. Both the balloon and the air inside it had a velocity of zero and therefore the total momentum was zero.

answer; (d) spontaneous processes are characterized by the overall conversion of order to disorder;

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.