A 2 kg ball is rolling down a hill at a constant speed of 4 m/s. When it is 5 m above the bottom of the hill, how much mechanical energy does the ball have? (Assume the bottom of the hill is 0 height)

An astronaut on the moon throws a baseball upward. the astronaut is 6 ft, 6 in. tall, and the initial velocity of the ball is 3030 ft per sec. the height s of the ball in feet is given by the equation s equals negative 2.7 t squared plus 30 t plus 6.5s=−2.7t2+30t+6.5, where t is the number of seconds after the ball was thrown. complete parts a and b.