Motion along a circular path at constant speed is classified as 'accelerated motion' because:

Correct Option

The correct option is

The direction of velocity changes continuously.

Explanation

Acceleration is defined as the rate of change of velocity with respect to time. Velocity is a vector quantity, meaning it is defined by both magnitude (speed) and direction. Consequently, a change in velocity can occur due to a change in magnitude, a change in direction, or both. Any such change results in accelerated motion.

Option Analysis

• The magnitude of velocity changes continuously. is Incorrect: In uniform circular motion, the object moves at a constant speed. Therefore, the magnitude of the velocity remains constant throughout the motion.
• The direction of velocity changes continuously. is Correct: In circular motion, the direction of the velocity vector is always tangential to the path. As the object moves along the circle, this direction changes continuously at every point. Since the direction of velocity changes, the velocity itself changes, resulting in acceleration (specifically, centripetal acceleration).
• The time period of rotation decreases. is Incorrect: If the speed is constant along a fixed circular path, the time taken to complete one revolution (time period) remains constant.
• The distance covered exceeds displacement. is Incorrect: While it is true that distance covered exceeds displacement in circular motion (except for an infinitesimal step), this is a geometric property of the path and not the definition or cause of acceleration.

Key Takeaway: Uniform circular motion is classified as accelerated motion because the direction of velocity changes continuously, even though the speed (magnitude) remains constant.