A child rolls a ball up a hill at 4.24 m/s. If the ball experiences an acceleration of -1.32 m/s^2, how long will it take for the ball to have velocity of 2.23 m/s down the hill?

v

_{f}=v_{i}+a*tv

_{i}=4.24 m/sv

_{f}=-2.23 m/s (why negative?)a=-1.32 m/s

^{2}Solve for t.