circular motion

(noun)

Motion in such a way that the path taken is that of a circle.

Related Terms

Examples of circular motion in the following topics:

  • Overview of Non-Uniform Circular Motion

    • Non-uniform circular motion denotes a change in the speed of a particle moving along a circular path.
    • What do we mean by non-uniform circular motion?
    • The answer lies in the definition of uniform circular motion, which is a circular motion with constant speed.
    • The circular motion adjusts its radius in response to changes in speed.
    • This means that the radius of the circular path is variable, unlike the case of uniform circular motion.

  • Circular Motion

    • Uniform circular motion describes the motion of an object along a circle or a circular arc at constant speed.
    • Therefore, uniform circular motion indicates the presence of a net external force.
    • The equation for the acceleration $a$ required to sustain uniform circular motion is:
    • In uniform circular motion, the centripetal force is perpendicular to the velocity.
    • Develop an understanding of uniform circular motion as an indicator for net external force

  • Kinematics of UCM

    • Uniform circular motion is a motion in a circular path at constant speed.
    • Under uniform circular motion, angular and linear quantities have simple relations.
    • Under uniform circular motion, the angular velocity is constant.
    • Any net force causing uniform circular motion is called a centripetal force.
    • For uniform circular motion, the acceleration is the centripetal acceleration: $a = a_c$.

  • Simple Harmonic Motion and Uniform Circular Motion

    • Simple harmonic motion is produced by the projection of uniform circular motion onto one of the axes in the x-y plane.
    • Uniform circular motion describes the motion of a body traversing a circular path at constant speed.
    • There is an easy way to produce simple harmonic motion by using uniform circular motion.
    • A point P moving on a circular path with a constant angular velocity ω is undergoing uniform circular motion.
    • Describe relationship between the simple harmonic motion and uniform circular motion

  • Relationship Between Linear and Rotational Quantitues

    • For example, consider the case of uniform circular motion.
    • This is the first advantage of describing uniform circular motion in terms of angular velocity.
    • For simplicity, let's consider a uniform circular motion.
    • Because $\frac{dr}{dt} = 0$ for a uniform circular motion, we get $v = \omega r$.
    • Each particle constituting the body executes a uniform circular motion about the fixed axis.

  • Circular Motion

    • Since the magnetic force is always perpendicular to the velocity of a charged particle, the particle will undergo circular motion.
    • So, does the magnetic force cause circular motion?
    • This is typical of uniform circular motion.
    • Uniform circular motion results.
    • Describe conditions that lead to the circular motion of a charged particle in the magnetic field

  • Angular Acceleration, Alpha

    • In circular motion, there is acceleration that is tangent to the circle at the point of interest (as seen in the diagram below).
    • In circular motion, centripetal acceleration, ac, refers to changes in the direction of the velocity but not its magnitude.
    • An object undergoing circular motion experiences centripetal acceleration (as seen in the diagram below.)
    • Centripetal acceleration occurs as the direction of velocity changes; it is perpendicular to the circular motion.
    • In circular motion, acceleration can occur as the magnitude of the velocity changes: a is tangent to the motion.

  • Helical Motion

    • Helical motion results when the velocity vector is not perpendicular to the magnetic field vector.
    • In the section on circular motion we described the motion of a charged particle with the magnetic field vector aligned perpendicular to the velocity of the particle.
    • In this case, the magnetic force is also perpendicular to the velocity (and the magnetic field vector, of course) at any given moment resulting in circular motion.
    • This produces helical motion (i.e., spiral motion) rather than a circular motion.
    • Uniform circular motion results.

  • Angular vs. Linear Quantities

    • The familiar linear vector quantities such as velocity and momentum have analogous angular quantities used to describe circular motion.
    • Similarly, circular motion is motion in a circle.
    • The angular velocity has a direction perpendicular to the plane of circular motion, just like a bike axle points perpendicularly to the rotating wheel.
    • Constant angular velocity in a circle is known as uniform circular motion.
    • A vector diagram illustrating circular motion.

  • Centripetal Force

    • A force which causes motion in a curved path is called a centripetal force (uniform circular motion is an example of centripetal force).
    • A force that causes motion in a curved path is called a centripetal force.
    • Uniform circular motion is an example of centripetal force in action.
    • where: $F_c$ is centripetal force, $m$ is mass, $v$ is velocity, and $r$ is the radius of the path of motion.
    • Angular velocity is the measure of how fast an object is traversing the circular path.