# Definition:Power (Physics)

Jump to navigation
Jump to search

*This page is about Power in the context of Physics. For other uses, see Power.*

## Definition

**Power** the amount of energy transferred or converted per unit time.

That is, the rate at which energy is transformed.

**Power** is a scalar quantity.

### Instantaneous

The instantaneous **power** transformed at an instant of time is defined as:

- $\map p t = \dfrac {\d \map E t} {\d t}$

where:

### Symbol

The usual symbols used to denote **power** are $P$ or $p$.

### Dimension

The dimension of measurement of **power** is $\mathsf {M L}^2 \mathsf T^{-3}$.

This derives from its definition as:

- $\dfrac {\text{Energy} } {\text {Time} }$

### Unit

The SI unit of **power** is the watt $\mathrm W$.

## Also see

## Sources

- 1976: Ralph J. Smith:
*Circuits, Devices and Systems*(3rd ed.) ... (previous) ... (next): Chapter $1$: Electrical Quantities: Definitions and Laws: Definitions: Table $1$-$2$: Important Derived Quantities - 1976: Ralph J. Smith:
*Circuits, Devices and Systems*(3rd ed.) ... (previous) ... (next): Chapter $1$: Electrical Quantities: Definitions and Laws: Definitions: Power