Centripetal force is the force that keeps an object moving along a circular path.

The term “centripetal” originates from the Latin words ‘centrum,’ meaning ‘center,’ and ‘petere,’ meaning ‘to seek.’ This fundamental concept in physics refers to the force acting on an object in circular motion, always directed toward the center of the circular path. Centripetal force is essential in maintaining an object’s circular trajectory, as it continuously alters the object’s direction of motion.

The magnitude of the centripetal force, $F$, acting on an object with mass $m$ that is moving at a speed $v$ along a circular path of radius $r$ is expressed by the formula:

This equation illustrates that the centripetal force increases with the square of the speed. For instance, if the speed is doubled, the centripetal force increases by a factor of four. Additionally, the centripetal force is inversely proportional to the radius of the path; if the radius is doubled, the centripetal force is halved.

Centripetal force can be generated by various forces, depending on the context. For example, in the case of a planet orbiting a star, the gravitational force between the planet and the star provides the necessary centripetal force. Conversely, when a car navigates a turn, the frictional force between the car’s tires and the road serves as the centripetal force.

It’s important to understand that centripetal force is not a distinct type of force; rather, it describes the role that various forces can play in circular motion. Additionally, there is a common misconception regarding a so-called “centrifugal” force that seems to act outward from the center of the circle. However, this is a fictitious force that appears only in a rotating reference frame. In reality, it is the centripetal force that keeps an object in circular motion.

Grasping the concept of centripetal force is vital in physics, as it helps explain various phenomena, including the orbits of planets, the functioning of centrifuges, and the dynamics of vehicles making turns. This concept is foundational in the study of circular motion and rotational dynamics.