# Uniform circular motion

As an object moves in a circle, it is constantly changing its direction. At all instances, the object is moving tangent to the circle. Since the direction of the velocity vector is the same as the direction of the object's motion, the velocity vector is directed tangent to the circle as well. The animation at the right depicts this by means of a vector arrow.  Left Ball in circular motion — rope provides centripetal force to keep ball in circle Right Rope is cut and ball continues in straight line with velocity at the time of cutting the rope, in accord with Newton's law of inertia, because centripetal force is no longer there.

In physicsuniform circular motion describes the motion of a body traversing a circular path at constant speed.

## Uniform Circular Motion

Since the body describes circular motion, its distance from the axis of rotation remains constant at all times. Though the body's speed is constant, its velocity is not constant: This changing velocity indicates the presence of an acceleration; this centripetal acceleration is of constant magnitude and directed at all times towards the axis of rotation.

This acceleration is, in turn, produced by a centripetal force which is also constant in magnitude and directed towards the axis of rotation. In the case of rotation around a fixed axis of a rigid body that is not negligibly small compared to the radius of the path, each particle of the body describes a uniform circular motion with the same angular velocity, but with velocity and acceleration varying with the position with respect to the axis.

Formulas[ edit ] Figure 1:When an object is experiencing uniform circular motion, it is traveling in a circular path at a constant speed.

## Uniform circular motion

If r is the radius of the path, and we define the period, T, as the time it takes to make a complete circle, then the speed is given by the circumference over the period. A similar. Orbital mechanics, also called flight mechanics, is the study of the motions of artificial satellites and space vehicles moving under the influence of forces such as gravity, atmospheric drag, thrust, etc.

Orbital mechanics is a modern offshoot of celestial mechanics which is the study of the motions of natural celestial bodies such as the moon and planets. Using the Interactive The Uniform Circular Motion Interactive is shown in the iFrame below. There is a small hot spot in the top-left corner.

 Keep Exploring Britannica This result agrees with the previous section, though the notation is slightly different. From the SparkNotes Blog Let us examine the equation for the magnitude of centripetal acceleration more practically. Consider a ball on the end of a string, being rotated about an axis. Get free, Daily Practice Problems! An object in UCM is constantly changing direction, and since velocity is a vector and has direction, you could say that an object undergoing UCM has a constantly changing velocity, even if its speed remains constant.

Some students find the transition from linear motion to circular motion a little confusing, but you needn't worry. Rotational kinematics, torque, kinetic energy, and . All objects in uniform circular motion must experience some form of uniform centripetal acceleration.

We find the magnitude of this acceleration by comparing ratios of velocity and position around the circle. Uniform Circular Motion DEFINITION OF UNIFORM CIRCULAR MOTION Uniform circular motion is the motion of an object traveling at a constant speed on a circular path.

Circular Motion