Physics 12 Santa Monica College H.-F. Lai Homework Solutions Ch. 2 Q10.
Velocity includes speed and direction of motion.
Constant velocity means both the speed and the direction of motion do not change. No, we cannot draw that conclusion. For example, a car moving on a circular track may have constant speed but it changes direction every instant, and therefore its velocity is changing every instant. Since the velocity does not change, the acceleration is zero. A freely falling object is free of all restraints - no friction, no air or otherwise, and moves under the influence of gravity alone, regardless of its initial motion.