Rolling motion occurs when an object, like a wheel or a ball, moves forward while rotating about its own axis. It is a combination of:
- Translational motion — the movement of the object’s center of mass in a straight line
- Rotational motion — the spinning of the object around its axis
In pure rolling (without slipping), the point of the object in contact with the surface is momentarily at rest relative to the surface. This means:
- The linear velocity of the center of mass is directly related to the angular velocity of rotation.
- Friction (usually static friction) is necessary to initiate and maintain rolling but does no work in pure rolling.
Examples of rolling motion:
- A bicycle tire on a road
- A bowling ball down an alley
- A marble rolling across a floor
Rolling motion is fundamental in physics and engineering, as it combines principles of both linear and rotational dynamics, making it crucial in understanding wheels, gears, and planetary motion.