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The speed of a body is a measure of the magnitude of its velocity, taking no account of its direction.

It is, therefore, a scalar quantity.


The usual symbol used to denote the speed of a body is $v$.


Speed of Sound in Air

The speed of sound in air at ground level on Earth is approximately $330 \, \mathrm {m s}^{-1}$.

Speed of Light

The speed of light (in a vacuum) is a physical constant.

Information cannot travel faster.

Also known as

Some authors erroneously or carelessly refer to the speed of a body as its velocity.

But this is technically wrong if the author does not specify its direction as well as its magnitude.

Also see

  • Results about speed can be found here.