Angular Speed Formula

Angular Speed Formula – Speed is simply the measurement of how fast or slow an object moves, for as how rapidly you drive your automobile. Now, we’re talking about a special form of speed. Angular speed is a sort of speed, however the body must follow a circular path. Angular speed is defined as the rate at which the central angle of a rotating body varies with respect to time. In this article, we will learn about angular speed.

Angular Speed Formula

Angular speed is defined as the rate of change of angular displacement, or the angle travelled by a body in a circular route. Angular speed is calculated by comparing the number of rotations/revolutions performed by a body to the time taken. Angular speed is symbolised by the Greek letter ‘ω’, or Omega. The SI unit for angular speed is rad/s.

The angular speed is calculated using two different formula,

  • ω = θ/t
  • ω = v/r

Angular Speed Formula Derivation

Despite the formula stated above, there is another and more widely used formula for calculation of angular speed from the point of view of competitive exams.

As ω = θ/t ⇢ (1)

Now we know that distance moved across arc of a circle is equal to radius times angle traversed. So,

s = rθ

=> θ = s/r ⇢ (2)

From (1) and (2),

Also from general understanding of linear speeds,

v = s/t ⇢ (4)

From (3) and (4),

ω = v/r

How to Find Angular Speed

The rate at which the central angle of a spinning body alters with respect to time is measured as the angular speed. The link between angular speed and linear speed, as well as a few angular speed puzzles, is known as the Angular Speed Formula.

The earlier use of the word speed in many contexts. For instance, people should be aware of how quickly they are driving or pitching. Similarly to that, speed essentially refers to how quickly or slowly the object is going. So, the rate at which an item rotates is determined by its angular speed. In other words, it is defined as the change in the object’s angle per unit of time.

Therefore, one will need to know the angular speed of the rotating motion in order to compute its speed. The body’s travel distance is calculated using the Angular Speed Formula by multiplying the number of revolutions or rotations by the travel duration.

Additionally, the radian plays a significant role in this. People measure the angle in radians in order to determine the angular speed. According to this method of calculating angles, radians, the correct angle is defined as pi/2 radians. Therefore, 6.28 radians make up a complete rotation.

The rate at which an object changes its angles, which we measure in radians in a given time, is what we see as the angular speed. The magnitude of the angular speed is a single value.

Symbol ω = Θ/ t


The angular speed is represented by the symbol ω as radians/sec.

The angle in radians is represented by the symbol θ (2π  radians = 360 degrees).

t is the time, in seconds.

It is significant to notice that both angular velocity and angular speed employ the same Angular Speed Formula. The difference between the two is that whereas angular velocity is a vector quantity, angular speed is a scalar quantity.

Conversion of Degree to Radian and Radian to Degree.

A radian is a common unit for measuring rotational angle. The ratio of the two distances, radius and arc length, is what is known as a radius (a dimensionless unit).

A full rotation around a circular object’s circumference takes up 2π radians, or 360 degrees. Radian and degree can be converted using this relationship because they are interchangeable terms.

1 revolution = 2π radians = 360-degree

Angular Velocity Solved Formula

Example 1: Consider a body travelling in a circular path of radius 8 m. It completes half a rotation in 8 seconds. Calculate the angular speed.
Solution:  In half revolution, the angle traversed is 180 degrees. In radians, it is equal to π radians.

ω = θ/t

=> ω = π/8 = 0.393 rad/s

Example 2: A car wheel of radius 4m is rotating with a linear speed of 40m/s. Calculate it’s angular speed.

Solution: ω = v/r

ω = 40/4

= 10 rad/s

Physics Related Formulas
Acceleration Formula Rotational Kinetic Energy Formula
Power Formula Wave Speed Formula
Velocity Formula Voltage Divider Formula
Average Speed Formula Static Friction Formula
Momentum Formula Average Force Formula
Pressure Formula Banking Of Road Formula
Torque Formula Deceleration Formula
Displacement Formula Drag Force Formula
Kinetic Energy Formula Elastic Collision Formula
Potential Energy Formula Electrical Resistance Formula

FAQs (Frequently Asked Questions)

1. Is angular speed consistently constant?

Every point on an object that is revolving about an axis has the same angular velocity. The tangential velocity of points distant from the axis of rotation is, nevertheless, different from that of points closer to the axis of rotation. The study material based on the Angular Speed Formula may be acquired by students from the Extramarks website or mobile application.

2. Are angular velocities conserved?

A spinning system’s ability to conserve angular momentum ensures that its spin will not change until it is subjected to an external torque; to put it another way, the rotation’s speed will not change as long as the net torque is zero.