In physics, circular motion is a movement of an object along the circumference of a circle or rotation along a circular path. It can be uniform, with constant angular rate of rotation (and constant speed), or non-uniform with a changing rate of rotation. The rotation around a fixed axis of a three-dimensional body involves circular motion of its parts. The equations of motion describe the movement of the center of mass of a body.
Examples of circular motion include: an artificial satellite orbiting the Earth at constant height, a stone which is tied to a rope and is being swung in circles, a car turning through a curve in a race track, an electron moving perpendicular to a uniform magnetic field, and a gear turning inside a mechanism.
Since the object's velocity vector is constantly changing direction, the moving object is undergoing acceleration by a centripetal force in the direction of the center of rotation. Without this acceleration, the object would move in a straight line, according to Newton's laws of motion.
Read more about Circular Motion: Uniform Circular Motion, Velocity, Acceleration, Non-uniform, Applications
Famous quotes containing the words circular and/or motion:
“The night in prison was novel and interesting enough.... I found that even here there was a history and a gossip which never circulated beyond the walls of the jail. Probably this is the only house in the town where verses are composed, which are afterward printed in a circular form, but not published. I was shown quite a long list of verses which were composed by some young men who had been detected in an attempt to escape, who avenged themselves by singing them.”
—Henry David Thoreau (1817–1862)
“I have seen in this revolution a circular motion of the sovereign power through two usurpers, father and son, to the late King to this his son. For ... it moved from King Charles I to the Long Parliament; from thence to the Rump; from the Rump to Oliver Cromwell; and then back again from Richard Cromwell to the Rump; then to the Long Parliament; and thence to King Charles, where long may it remain.”
—Thomas Hobbes (1579–1688)