## J : Sound and Vibration Definitions, Terms, Units, Measurements ...

**Jerk** a vector quantity that specifies time rate of change of acceleration - units m/s^{3}

**Joule (J)** the derived

SI unit of

work or

energy.

A Joule is the work done by a force of 1 newton acting through a distance of one metre.

Joule = N·m = Kg·m^{2}/s^{2} = W·s = Pa·m^{3} = 10^{7} ergs = C·V

where kg is the

kilogram, m is the

metre, s is the

second, N is the

newton, Pa is the

pascal, W is the

watt, C is the

coulomb, and V is the

volt.

**joule per cubic metre (J/m**^{3}) ▷ see Sound Energy Density

**joule per kilogram (J/kg)** ▷ see Specific Energy

**joule per second (J/s)** ▷ see Sound Power

**Judged Perceived Noise Level Definition** IEC 801-29-10, sound pressure level, in decibels, of a frontally presented

octave band of

pink noise centred on 1 kHz and lasting for two seconds, that is subjectively judged equally noisy as a given sound

See also • perceived noise level

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