Circular motion. Introduction

Do you want to know in more detail what circular motion is and how it acts on an object?

The online circular motion simulations on this page will allow you to deepen your knowledge of circular motion and in particular of two of its variables, velocity and angular acceleration.

Circular motion is the motion in which an object moves around a fixed point in a circular path. This type of motion can be uniform, when the angular velocity is constant, or non-uniform, when the angular velocity varies.

For circular motion to occur, there must be a centripetal acceleration directed towards the center of the circular path. This acceleration is necessary to keep the object in its circular path, because if there were no force acting on the object, it would move in a straight line. The magnitude of the centripetal acceleration depends on the velocity of the object and the radius of the path.

The angular velocity determines how fast the object moves around the fixed point. Angular velocity is measured in radians per second.

The period is the time required for the object to complete one full revolution around the fixed point. The period is related to the angular velocity and the radius of the path by the equation T = 2π/ꙍ, where T is the period and ꙍ is the angular velocity.

Circular motion has many practical applications, such as, for example, the manufacture of wheels, gears and pulleys or the dynamics of planets and satellites. In addition, circular motion is used in physics and engineering to describe the trajectory of subatomic particles and the rotation of molecules and atoms.

Below are several simulations and other educational resources, which can also serve as very illustrative examples. In addition, a selection of books and courses is included to help you broaden your knowledge of this subject.

Motion
Velocity
Acceleration I
Acceleration II
Car

Circular motion

This simulation shows what circular motion looks like. Observe the relationship between period, radius and linear velocity.

Change of velocity in circular motion

This animation shows the change of the velocity vector in a circular motion. Click on the boxes of the different steps (1, 2...) and observe the results.

Centripetal acceleration

This animation shows the velocity and acceleration vectors in a circular motion.

Circular acceleration

Car in a circular motion

When a car moves in a circular motion, centripetal force is generated by friction with the surface. On a wet surface, the friction is reduced, the car will tend to move outwards.