CHAPTER 14

Energy

1 . A 2 kg mass experiences a potential energy that varies with x as shown in the graph. Which statement
correctly describes the behavior of the mass?
(A) When at a location of 1 m, the mass will experience a force in the negative x direction.
(B) When at a location of 1 m, the mass will experience no force.
(C) If released from rest at a location of 3 m, the mass will reach a maximum speed of .
(D) If released from rest at a location of 3 m, the mass will oscillate about an equilibrium at location
of 2 m on the x -axis.
(E) If released from rest at a location of 5 m, the mass will reach a maximum speed of 20 m/s.

2 . An 80 kg roller-coaster car traveling 10 m/s passes over the crest of a 40 m hill, as shown in the
figure. The speed of the car at the bottom of the hill is 24 m/s. The energy lost to friction is most
nearly
(A) 60 J