A ball is projected upward at time t = 0 s, from a point on a flat roof 90 m above the ground. The ball rises and then falls with insignificant air resistance, missing the roof, and strikes the ground.
The initial velocity of the ball is 80.5 m/s. Consider all quantities as positive in the upward
Direction. The vertical velocity of the ball when it is 89 m above the ground is closest to
A) -81 m/s.
B) -48 m/s.
C) -32 m/s.
D) -64 m/s.
E) -97 m/s.

Question

Quizplus · Accepted Answer

The correct answer is A because the ball is projected upward with an initial velocity of 80.5 m/s, and it rises to a maximum height of 90 m above the ground. The ball then falls with insignificant air resistance, and its vertical velocity when it is 89 m above the ground is closest to -81 m/s.

A Ball Is Projected Upward at Time T = 0