Question

1. which describes acceleration involving only a change in direction? (1 point)

moving at constant speed around a circular track
an object in free fall
an object at rest
moving at increasing speed around a curve

Explanation:

• When an object is moving at a constant speed around a circular track, its speed (magnitude of velocity) remains the same. But since it is moving in a circular path, its direction is constantly changing. Acceleration is the rate of change of velocity. Velocity is a vector quantity (has both magnitude and direction). So, a change in direction of velocity means there is an acceleration (centripetal acceleration).
• For an object in free - fall, its speed is changing (increasing due to gravity), so there is a change in both magnitude and direction (if we consider projectile - like free - fall, but even in straight - line free - fall near the surface of the Earth, the magnitude of velocity is changing).
• An object at rest has zero velocity and no change in velocity (both magnitude and direction), so no acceleration.
• When moving at increasing speed around a curve, both the magnitude (speed) and direction of velocity are changing.

Answer:

moving at constant speed around a circular track