The ball has 7.35 joules of potential energy at position B. At position A, all of the energy changes to kinetic energy. The velocity of the ball at position A is meters/second. Assume there’s no air resistance. Use g = 9.8 m/s2 , PE = m × g × h, and . mass is 1.5 kilograms and g= 9.8 and the hight of position b is 0.5 meters.