When you see Marjorie, she is swinging a bucket of water around in a circle. The speed of the bucket of water does not change as it moves in the circle. Which of the following statements best explains how you could tell that a net force is constantly acting on the bucket of water?
A. The bucket of water is not at rest.
B. The bucket of water is speeding up or slowing down.
C. The bucket of water began at rest, and you saw it begin to move.
D. The bucket of water's direction is changing, instead of moving in a straight line.