A Rock, Tied at the End of a Rope, Is

Multiple Choice

A rock, tied at the end of a rope, is swirled in a vertical circle (the rock's speed changes during the motion) . The work done on the rock by the tension in the rope

A) is positive.
B) is zero.
C) is negative.
D) changes from positive to negative and back as the velocity of the rock changes its direction.
E) depends on the weight of the rock.