Centripetal acceleration changes which aspect of velocity?

Centripetal acceleration changes which aspect of velocity?

• A. Changes the direction of the velocity.
• B. Changes the magnitude of the velocity.
• C. Changes the magnitude of angular velocity.
• D. Changes nothing about velocity.

Answer: (A)

In circular motion, velocity is a vector, so what matters is how its direction and magnitude change. Centripetal acceleration points toward the center of the circle and is always perpendicular to the velocity. Because acceleration is what changes velocity, this inward acceleration bends the velocity vector—the path curves—without changing its speed. The speed would only change if there were a component of acceleration along the direction of motion (a tangential component). So centripetal acceleration changes the direction of velocity, not its magnitude, which is why the best answer is that aspect.

In circular motion, velocity is a vector, so what matters is how its direction and magnitude change. Centripetal acceleration points toward the center of the circle and is always perpendicular to the velocity. Because acceleration is what changes velocity, this inward acceleration bends the velocity vector—the path curves—without changing its speed. The speed would only change if there were a component of acceleration along the direction of motion (a tangential component). So centripetal acceleration changes the direction of velocity, not its magnitude, which is why the best answer is that aspect.