## 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.
73.What is the direction of the average acceleration during this time interval?
(A) →
(B) ←
(C) ↓
(D) The average acceleration is zero.