A block of weight mg = 100 N slides a distance of 5.0 m down a 30-degree incline, as shown above.
1 . How much work is done on the block by gravity?
(A) 500 J
(B) 430 J
(C) 100 J
(D) 50 J
(E) 250 J2 . If the block experiences a constant friction force of 10 N, how much work is done by the friction
force?
(A) −43 J
(B) −25 J
(C) −500 J
(D) −100 J
(E) −50 J3 . A mass experiences a potential energy U that varies with distance x as shown in the graph above. The
mass is released from position x = 0 with 10 J of kinetic energy. Which of the following describes the
long-term motion of the mass?
(A) The mass eventually comes to rest at x = 0.
(B) The mass slows down with constant acceleration, stopping at x = 5 cm.