A ball of diameter d makes x revolutions when rolling a distance d on the floor. Find the distance d of the ball rolls in terms of d and x.

If its history of, then b) because a) implies only present day (now)

Ke reqd to move from 0 to 50 will be proportional to 50x50 or 2500. this is equal to w.  to change vel from 50 to 150 you need energy prop to 22500 - 2500 = 20,000. this corresponds to 8w.  best answer is a) . work reqd is prop to velocity squared. 

A). redi wish i´ve

Bis the answerhope it !