When an object moves along a circular path at a constant speed, its velocity changes continuously due to the change in direction. However, the horizontal component of velocity remains constant because it remains unchanged throughout the motion.
To understand this concept, let's consider a particle moving in a circular path. The velocity of the particle is a vector quantity that has both magnitude and direction. It can be decomposed into two components: the horizontal component and the vertical component.
As the particle moves along the circular path, its direction constantly changes towards the center of the circle. This change in direction affects only the vertical component of velocity, causing it to vary. However, the horizontal component of velocity remains unaffected because the motion is constrained to the circular path and does not involve any change in the horizontal direction.
To illustrate this, imagine a car moving around a racetrack. The car's speed remains constant, but its direction is constantly changing to follow the curvature of the track. The horizontal component of its velocity, which determines how fast it is moving along the track, remains constant throughout the motion. Meanwhile, the vertical component of velocity, which determines the car's position above or below the track, may vary depending on the incline or decline of the track.
In summary, the horizontal component of velocity remains constant when moving along a circular path because the circular motion only affects the direction of motion, not the component of velocity in the direction perpendicular to the path.