A ball is thrown directly upward into the air. The graph below shows the vertical position of the ball with respect to time. a. How much time does the ball take to reach its maximum height? b. How much time does the ball take to reach one-half its maximum height? c. Estimate the slope of ∆y/∆t at t = 0.05 s, t = 0.10 s, t = 0.15 s, and t = 0.20 s. On your paper, draw a coordinate system with velocity (v) on the y-axis and time (t) on the x-axis. Plot your velocity estimates against time. d. From your graph, determine what the acceler- ation on the ball is.

W= fd
where f is an applied force and d is the distance over which it is applied. when a parachuting skydiver is at constant velocity, he is experiencing "terminal velocity", the point at which his acceleration down is canceled out by air resistance. that means that the resisting force of the air is equal to his weight, but in the opposite direction. with this, we can solve for the work done by the force.
w = fd
w = (92.0)(9.81 m/s^2) (325)
w= 2.93 x 10^5 j
the value for work in this case is positive because it is pushing up on the skydiver, who has a downward force of gravity.
therefore the answer is 2.93 x 10^5 j