An Olympic sprinter can start from rest and reach a top velocity of 11.5m/s, in the first 15.0m of a race. A)What average acceleration does the sprinter have to have to achieve this Velocity? B) How much time does it take the sprinter to achieve that velocity?

This is kenetic energy.

Make them both to where they have the denominator of 18that makes 3/2 equal 27/18 and 1/9 equal 2/18so now you have  27/18x+5=2/18subtract 5 from the other sideso now you have 27/18x+2/18-5then subtract 2/18 from 27/18 to get 25/18x=-5then divide 25/18 by -5 and your answer will be  -5/18