posted by Ashley .
A ball thrown upward reaches a height of 13m. How much time did it take to get to this height? How much time will take to fall to the ground?
V =sqrt(2*9.8*13) that is the initial velocity.
the average velocity going up is half that, so time up= 12/(1/2 sqrt(2*9.8*13)
grab your calculator.
Time down is the same as time up.