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Velocity Units: Definitions, Examples, Si Units, Other Units, and Velocity Vs Speed

Nikita Parmar

Updated on 26th October, 2023 , 5 min read

Velocity Units Overview

Velocity is a fundamental notion in physics that assesses the rate at which an object's location changes over time. Velocity is defined as the speed of an item measured in a given direction. Also known as velocity is the time-rate change of displacement. Both speed and velocity are quite close to one another. However, there is a significant distinction in that velocity is a vector variable with both magnitude and direction. And speed is a scalar quantity with just magnitude. Thus, velocity measures how long it takes a body to travel in a straight line to a destination.

What is Velocity?

The rate of change of an object's location about a frame of reference and time is defined as velocity. Velocity is a vector measure of movement speed and direction. Simply explained, velocity is the rate at which something goes in one direction or another. Speed may be used to quantify the speed of a car driving north on a major highway or the speed of a rocket blasting into space. The scalar size (total value) of vector velocity indicates the speed of movement, as one might expect. In terms of calculations, speed is the first timed exit from a location. A simple formula based on measurement, distance, and time may be used to compute speed.

Velocity Units

Examples of Velocity

For example, if two objects are traveling in the same direction, it is easy to determine which is faster. However, if the two items are moving in different directions, it is impossible to determine which is faster. In such cases, the idea of velocity is critical.

Velocity Units

Velocity Units Meaning

According to the definition of velocity, it is the rate of change of an object's location about a frame of reference and time. It may appear difficult, but velocity is just speed in a specified direction. Because velocity is a vector quantity, we must define it in terms of both magnitude (speed) and direction. It is measured in meters per second (ms-1). When the amount or direction of a body's velocity changes, it is said to be accelerating.

What is the SI Unit of Velocity?

The unit of velocity is defined as the ratio between the units of distance and time. Students should not mix up velocity with speed because they are not the same thing. Although the units of speed and velocity are identical, velocity is defined as the rate at which an object changes its location about a time and reference frame. The velocity formula is as follows- 

Velocity = Displacement/Time or v = s/t

V is the velocity

s is displacement

t is the time taken

Remember that displacement is normally expressed in meters, while time is expressed in seconds. As a result, velocity is measured in meters per second (m/s).

The meter per second (m/s) is the SI unit of velocity.

The magnitude of velocity can alternatively be given in centimeters per second (cm/s).

Read more about the Orbital Velocity Formula.

Unit of Velocity 

The rate at which velocity varies is called acceleration, whereas the rate at which location changes concerning time is called velocity. Both are vector numbers (and hence have a specified direction), although velocity is measured in meters per second and acceleration in meters per second squared.

S.I. Unit of Velocity

The meter/second is the SI unit of velocity.

C.G.S. Unit of Velocity

CGS Unit of Velocity The CGS unit of velocity is cms-1.

S.I. Unit of Angular Velocity

Radians per second is the SI unit of angular velocity. Because the radian has no dimensions, the SI unit of angular velocity is represented as s-1. The symbol is used to represent angular velocity.

S.I. Unit of Drift velocity

Drift velocity is the average velocity attained by electrons in the presence of an electric field. The drift velocity is measured in meters per second (m/s) or meters per second (m2/V.s).

Read more about the Drift Velocity Formula.

S.I. Unit of Average Velocity

The average velocity of an item is its displacement concerning its original position divided by time. It is, in other words, the pace at which an item travels over time. The standard international unit of average velocity is meters per second (m/s).

Unit of Relative Velocity

The speed with which one item moves concerning another is defined as its relative velocity. The velocity unit is defined as the ratio of the distance and time units. The speed of light is measured in meters per second (m/s).

Average Velocity

The ratio of total displacement to total time taken by the item is known as average velocity.

Average velocity = total displacement / total time

The average velocity has the same SI unit as the velocity. Its dimensional formula is also the same.

Unit of Velocity of Light

Light corresponds to a certain section of the electromagnetic spectrum. The speed of light is a basic constant with a value of 3 x 10¹⁰ centimeters per second. The unit of velocity is the same as the unit of light velocity. It can be represented in m/s, km/hr., and other units.

Angular Velocity

The angular velocity of an object in circular motion is defined as its velocity. It is defined as the angular displacement rate of change. It is symbolized by the Greek letter Omega (𝛀). A vector quantity is angular velocity. It has the same direction as the angular displacement. Radians per second is the SI unit of angular velocity. In this case, radian is a dimensionless quantity. The SI unit of angular velocity is 1/ s or second⁻¹ or s⁻¹.

In S.I. base units: s⁻¹.The dimensional formula for angular velocity: M⁰L⁰T⁻¹M⁰L⁰T⁻¹

Angular Displacement

Displacement is defined as the angle formed by the path traced by an item in circular motion.

Angular displacement (Ө) = arc / radius

The dimensionless unit of angular displacement is the radian.

Read more about the Difference between Displacement and Distance and SI Unit of Displacement

Other Velocity Units

Other units that identify velocity include-

  1. Benz (Bz)
  2. Centimeters per hour (cmph)
  3. Centimetre per minute
  4. Feet per minute or ft/ m or fpm
  5. Foot per hour
  6. Foot per second or ft /s or fps
  7. Inch per second
  8. Kilometers per hour (km/hr)
  9. Kilometers per second (kps)
  10. Knot (unit)
  11. Meter per hour (m/hr)
  12. Metre per minute
  13. Miles per hour
  14. Mile per minute
  15. Millimetres per minute (mmpm)
  16. Millimeter per second (mps)
  17. Speed of light

Difference Between Speed and Velocity: Velocity Units

A full comparison in tabular style is provided below-

Speed

Velocity

Speed is a quantitative measure of how fast something moves.

The direction of movement of the body or item is defined by velocity.

It is the pace at which distance changes.

It is the displacement rate of change.

Speed is fundamentally a scalar number.

Velocity is, in essence, a vector quantity.

A moving object's speed can never be negative.

A moving object's velocity can be zero.

It is defined as the distance an item travels in one unit of time.

The displacement of an item in unit time is defined as velocity.

The object's speed is a good measure of its speed.

The primary indication of an object's position and speed is its velocity.

Velocity Units

Frequently Asked Questions

What exactly is velocity?

Ans. The velocity of an item is often described as the rate of movement that a particle or object experiences over time. Velocity is defined as a physical vector quantity, which means that it must be defined in terms of both direction and magnitude.

Is it possible to add vector quantities algebraically?

Ans. Because vector values contain orientations in addition to magnitude, they cannot be added algebraically. Furthermore, directions cannot be added algebraically.

When a ball is tossed in the air, what happens to its velocity and acceleration?

Ans. When the ball is tossed into the air, its velocity and acceleration both rise.

What exactly is displacement?

Ans. Displacement is described as a change in a body's position.

What is the distinction between speed and velocity?

Ans. There is a significant difference between the two; for example, velocity tells us about the speed of the object and the direction in which it is moving, whereas speed tells us how fast the object is moving.

What is the SI unit of speed?

Ans. Velocity is measured in meters per second (m/s). The magnitude of velocity can alternatively be given in centimeters per second (cm/s).

What exactly is instantaneous speed?

Ans. The speed of an item at a certain point in time is defined as instantaneous speed.

What does the velocity-time graph serve?

Ans. The velocity-time graph is used to explain an object's continual acceleration.

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