Final answer:
No, it is not possible for an object to have constant speed and changing velocity. Yes, it is possible for an object to have changing speed and constant velocity.
Step-by-step explanation:
a) No, it is not possible for an object to have constant speed and changing velocity. Velocity is a vector quantity that includes both speed and direction. If an object's velocity is changing, it means either its speed is changing or its direction is changing, or both. So if speed is constant, the velocity cannot be changing.
b) Yes, it is possible for an object to have changing speed and constant velocity. Constant velocity means that the object is moving in a straight line at a constant speed. So, even if the object's speed is changing, as long as it remains in a straight line, its velocity will be constant.