A ball is projected upward at time t = 0.0 s from a point on a roof 90 m above the ground. The ball rises, then falls and strikes the ground. The initial velocity of the ball is The velocity of the ball when it is above the ground is about _____: -64 m/s
-81 m/s
-97 m/s
-32 m/s
-48 m/s
