What causes an object to move in a circular path?

An object moves in a circular path due to a force acting towards the centre of the circle, known as centripetal force.

Centripetal force is the key factor that causes an object to move in a circular path. This force is always directed towards the centre of the circle and keeps the object moving along the circular path. Without this force, the object would continue to move in a straight line due to inertia.

The term 'centripetal' comes from the Latin words 'centrum', meaning centre, and 'petere', meaning to seek. So, centripetal force can be thought of as a 'centre-seeking' force. It is this force that constantly changes the direction of the object's velocity, making it move in a circle.

The magnitude of the centripetal force required to keep an object moving in a circular path depends on three factors: the mass of the object, the speed of the object, and the radius of the circle. The greater the mass or speed of the object, or the smaller the radius of the circle, the greater the centripetal force needed.

It's important to note that centripetal force is not a new kind of force. It can be provided by various forces like gravity, tension, friction, or a combination of these. For example, the Earth moves in a circular path around the Sun due to the gravitational pull of the Sun, which acts as the centripetal force. Similarly, a car moving in a circular path is kept on track by the friction between its tyres and the road, which provides the necessary centripetal force.

In conclusion, an object moves in a circular path because of the centripetal force acting towards the centre of the circle, constantly changing the object's direction of motion.