Uniform Circular Motion

The video introduces uniform circular motion through examples like a ball on a rope, a sticker on a fan blade, and the Earth orbiting the Sun. It breaks down the term: 'motion' means movement, 'circular' means a circular path, and 'uniform' means constant speed.

Although the speed is constant in uniform circular motion, the velocity is not constant because the direction of motion continuously changes. The direction of velocity at any instant is tangential to the circle.

Uniform circular motion is an accelerated motion because the velocity changes due to the continuous change in direction. The acceleration, known as centripetal acceleration, is always directed towards the center of the circle and is perpendicular to the velocity.

An inward force, called centripetal force, is responsible for maintaining uniform circular motion. This force is always directed towards the center of the circle. Examples include the tension in a rope for a swinging ball and the Sun's gravitational pull on the Earth.

While often used as an example, the Earth's orbit around the Sun is not strictly uniform circular motion because its path is elliptical and its speed varies. However, it is commonly approximated as such for simplicity.

The speed in uniform circular motion is calculated using the formula: speed = distance / time. For one full revolution, the distance is the circumference (2πr) and the time is the period (T), so speed = 2πr/T.