Centripetal force is the net force that keeps an object moving in a circular path. It always acts toward the center of the circle, constantly pulling the object inward and preventing it from moving off in a straight line due to inertia.
Although an object in circular motion appears to be “spinning around,” it’s actually constantly accelerating because its direction is changing—even if its speed remains constant. This change in direction requires a force, and that’s the centripetal (meaning “center-seeking”) force.
The source of this force depends on the situation:
- For a car turning on a curved road, friction between tires and road acts as the centripetal force.
- For planets orbiting the Sun, gravity provides the centripetal force.
- For a ball on a string being whirled around, the tension in the string is the centripetal force.
Without this inward force, the object would move off in a straight line due to Newton’s First Law of Motion. So, centripetal force doesn’t make the object speed up—it changes its direction, keeping it in a circular path.