## Questions 72-73
A particle continuously moves in a circular path at constant speed in a counterclockwise direction. Consider a time interval during which the particle moves along this circular path from point P to point Q . Point Q is exactly half-way around the circle from Point P.
72. What is the direction of the average velocity during this time interval?
(A)→
(B) ←
(C) ↑
(D) The average velocity is zero.