Here's why:
* Centripetal Force: This force is directed towards the center of the circular path. It's what keeps the object moving in a circle rather than continuing in a straight line.
* Velocity: An object's velocity is always tangent to the circular path.
* Perpendicularity: Since the centripetal force is directed towards the center and the velocity is tangent to the circle, they are always perpendicular to each other.
This perpendicular relationship is crucial for circular motion:
* No Work Done: Because the force is perpendicular to the motion, the centripetal force does no work on the object. This means the object's speed doesn't change, only its direction.
* Continuous Change in Direction: The centripetal force constantly changes the direction of the object's velocity, resulting in circular motion.
Examples of centripetal force:
* Gravity: Keeps planets in orbit around the sun.
* Tension in a String: Keeps a ball swinging in a circle.
* Friction: Allows a car to turn on a curve.
