A 72.0-kg man is riding an escalator in a shopping mall. The escalator moves the man at a constant velocity from ground level to the floor above, a vertical height of 3.70 m. What is the work done on the man by (a) the gravitational force and (b) the escalator?
A 82.8-g arrow is fired horizontally from rest. The bowstring exerts an average force of 62.5 N on the arrow over a distance of 0.908 m. With what speed does the arrow leave the bow?
A basketball player makes a jump shot. The 0.610-kg ball is released at a height of 2.23 m above the floor with a speed of 7.85 m/s. The ball goes through the net 3.29 m above the floor at a speed of 5.25 m/s. What is the work done on the ball by air resistance, a nonconservative force?
W=F*S where the displacement is pointint upward.
For the gravational force, it is pointing downward. ...
With full formulas and calculations, the problems are solved.