Aball is thrown directly upward from a height of 8 ft with an initial velocity of 20 ft/sec. the function s(t) = −16t²+20t+8 gives the height of the ball, in feet, t seconds after it has been thrown. a. determine the time at which the ball reaches its maximum height and find the maximum height. b. how long after the ball is thrown does it land back on the ground?

In a system with only a single force acting upon a body, what is the relationship between the change in kinetic energy and the work done by the force? answers: work is equal to the change in kinetic energy.work depends on the square of the change in potential energy.work is equal to the negative of the change in kinetic energy.work is equal to the square of the change in kinetic energy