Circular motion in physics. Characteristics, types and simulations

21/04/2026

The online circular motion simulations on this page will allow you to deepen your knowledge of this important type of motion. We will discover what are the main characteristics of circular motion in physics and the most important types of circular motion

This Thematic Unit is part of our Physics collection

Angular Displacement

Angle swept by an object in circular motion, generally measured in radians.

Angular Velocity

Rate at which an object’s angular displacement changes per unit of time.

Circular Motion

Motion of an object traveling along a curved path with a constant radius relative to a fixed point.

Frequency

Number of complete turns or revolutions an object makes in a given unit of time.

Period

Time required for an object in circular motion to complete one full revolution or turn.

Radian

Angle measurement unit in the SI representing the central angle whose arc length is equal to the radius; it is approximately equal to 57.29°.

Radius of Rotation

Constant distance between the center of the circular path and the position of the moving particle.

Revolution

Complete turn of an object around an axis, equivalent to an angle of 360 degrees or 2π radians.

What is circular motion in physics

Circular motion in physics is the motion in which an object moves around a fixed point in a circular path.

Characteristics of circular motion in physics

The main characteristics of circular motion in physics include the presence of a closed trajectory around a fixed point and the need for forces to keep the object on that trajectory. The object describes a circle, so that at each instant its velocity has a tangent direction to the trajectory, while the centripetal acceleration always points towards the center of the circle. In circular motion it is essential to consider two quantities: the angular velocity and the period.

Angular velocity

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

Period

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.

Types of circular motion in physics

There are mainly two types of circular motion: uniform circular motion (UMC) and non-uniform circular motion (NCM).

Uniform circular motion (UCCM)

In UCCM, both the magnitude of the velocity and the centripetal acceleration remain constant, allowing the object to travel equal distances in each time interval.

Non-uniform circular motion (NUCM)

In NUCM, the object experiences changes in angular velocity, so angular acceleration comes into play, changing how fast the object rotates around the fixed point.

Understanding the difference between these two types is essential for analyzing real situations involving forces and velocity variations, such as the rotation of wheels or the ride of a roller coaster.

Applications of circular motion

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.

These online circular motion simulations will be a great help for you to learn more about this important type of motion.

Angular Displacement

Angle swept by an object in circular motion, generally measured in radians.

Angular Velocity

Rate at which an object’s angular displacement changes per unit of time.

Circular Motion

Motion of an object traveling along a curved path with a constant radius relative to a fixed point.

Frequency

Number of complete turns or revolutions an object makes in a given unit of time.

Period

Time required for an object in circular motion to complete one full revolution or turn.

Radian

Angle measurement unit in the SI representing the central angle whose arc length is equal to the radius; it is approximately equal to 57.29°.

Radius of Rotation

Constant distance between the center of the circular path and the position of the moving particle.

Revolution

Complete turn of an object around an axis, equivalent to an angle of 360 degrees or 2π radians.

Explore the exciting STEM world with our free, online, simulations and accompanying companion courses! With them you’ll be able to experience and learn hands-on. Take this opportunity to immerse yourself in virtual experiences while advancing your education – awaken your scientific curiosity and discover all that the STEM world has to offer!

Circular motion simulations

Conditions
Acceleration

Circular motionconditions

This simulation allows us to study the conditions under which circular motion occurs. Find out the angle that the velocity and acceleration must form for the motion to be circular. What happens if the angle is greater? What happens if the angle is smaller?

Circular acceleration

Motion
Velocity
Acceleration I
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.

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.

Giants of science

“If I have seen further, it is by standing on the shoulders of giants”

Isaac Newton

William Rowan Hamilton

1805

–

1865

William Rowan Hamilton developed Hamiltonian mechanics and quaternions, unifying geometry and mathematical physics

“Mathematics and physics meet in the harmony of the equations governing motion.”

Galileo Galilei

1564

–

1642

Galileo Galilei revolutionized astronomy by observing planets, Jupiter’s moons, and advocating heliocentrism.

“And yet it moves”

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Giants of science

“If I have seen further, it is by standing on the shoulders of giants”

Isaac Newton

Galileo Galilei

1564

–

1642

Galileo Galilei revolutionized astronomy by observing planets, Jupiter’s moons, and advocating heliocentrism.

“And yet it moves”

Archimedes

287 a.C.

–

212 a.C.

Archimedes established fundamental principles of mechanics and hydrostatics, including the famous Archimedes’ principle of buoyancy in fluids

“Give me a place to stand, and I will move the world”

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Free mode

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Dynamics and Control

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Test your knowledge

What is circular motion, and which quantities describe it in physics?

Circular motion is motion in which an object travels along a circular path around a fixed point. In this type of motion, the direction of the velocity changes continuously, even if its magnitude remains constant. To describe it properly, specific quantities are used: angular velocity, which indicates how fast the object rotates and is measured in radians per second, and the period, which represents the time needed to complete one full revolution. Frequency, which expresses how many revolutions occur per second, is also used. The relationship among these quantities allows the system to be analyzed without considering forces. Circular motion may be uniform, when angular velocity is constant, or non‑uniform, when it varies with time. These concepts are essential for understanding rotational phenomena in physics and engineering.

How do uniform circular motion and non‑uniform circular motion differ?

Uniform circular motion (UCM) is characterized by a constant angular velocity, meaning the object covers equal arcs in equal time intervals. Although the speed does not change, the direction of the velocity does, producing a centripetal acceleration directed toward the center of the path. In non‑uniform circular motion (NUCM), the angular velocity varies with time, so an angular acceleration appears, modifying how fast the object rotates. This distinction is essential for analyzing real situations such as wheels speeding up or slowing down, turbines changing operating regimes or rotating systems subject to variations in speed. Understanding both types of motion allows accurate descriptions of rotational behavior in ideal and practical contexts.

Why does velocity change in circular motion even when the object “moves at the same speed”?

In circular motion, even if the object moves with the same speed along the path, its velocity changes because its direction is constantly changing. Velocity is not only “how fast you go” but also “where you are heading.” Since the direction of motion rotates continuously along a circle, the velocity is never exactly the same. This is why we say there is acceleration even when the speed is constant.

What do angular velocity and period mean in circular motion?

Angular velocity indicates how fast an object rotates around a fixed point and is measured in radians per second. The period is the time required to complete one full revolution. These quantities are related by the equation (T = 2π/ꙍ). If angular velocity increases, the period decreases, and vice versa. These ideas allow circular motion to be described without studying forces, focusing instead on how the angular position changes over time.

What everyday examples help illustrate circular motion?

Circular motion appears in many rotating objects: bicycle wheels, fans, hard‑drive disks, gears or planets orbiting the Sun. In all these cases, the object follows a circular path and repeats its motion periodically. Observing these examples helps clarify concepts such as angular velocity, period and frequency. It also makes it easier to distinguish between motion with constant rotation speed and motion where the rotation speeds up or slows down.