In classical mechanics, an impulse changes the momentum of an object. An impulse is calculated as the integral of force with respect to duration.
- <math>\mathbf{I} = \int \mathbf{F} dt </math>
Using the definition of force yields:
- <math>\mathbf{I} = \int \frac{d\mathbf{p}}{dt} dt </math>
- <math>\mathbf{I} = \int d\mathbf{p} </math>
- <math>\mathbf{I} = \Delta \mathbf{p} </math>
See also specific impulse.
The term can also refer to any short-duration signal such as a
nerve impulse, or a notional signal used to calculate
impulse response[?], in the continuous case the
Dirac delta function.