Circular motion

In kinematics, circular motion is the motion of an object along a circular path. Examples of this include a stone tied to a string, a car moving around a curve, and a point on a rotating wheel. Circular motion can be uniform, meaning the speed is constant, or non-uniform, meaning the speed changes. Even in uniform circular motion, the object is accelerating because its velocity changes direction. The object accelerates toward the center of the circle; this inward acceleration is called centripetal acceleration. A force toward the center, called centripetal force, is required to produce this acceleration. Circular motion is also used to describe the motion of points in a rigid body rotating about a fixed axis, in which case each point in the body moves in a circle fixed around the axis of rotation.

More examples of circular motion include special satellite orbits around the Earth (circular orbits), a ceiling fan's blades rotating around a hub, an electron moving perpendicular to a uniform magnetic field, and a gear turning inside a mechanism.

Without centripetal acceleration, the object would move in a straight line, according to Newton's laws of motion.

This article is issued from Wikipedia. The text is available under Creative Commons Attribution-Share Alike 4.0 unless otherwise noted. Additional terms may apply for the media files.