Difference between revisions of "Power (Physics)"
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| − | In physics, power refers to the rate of [[Work|transfer of energy]] respect to [[time]]. | + | In physics, power refers to the rate of [[Work|transfer of energy]] respect to [[time]] |
| + | <ref>Serway and Beichner, ''Physics For Scientists and Engineers'', Fifth Edition</ref>. | ||
Mathematically, average power is expressed as: | Mathematically, average power is expressed as: | ||
| Line 14: | Line 15: | ||
The usual units for power are [[Watts]] ( W = [[Joule|J]]/[[seconds|s]] ) and [[horsepower]] ( hp = 746 W ) | The usual units for power are [[Watts]] ( W = [[Joule|J]]/[[seconds|s]] ) and [[horsepower]] ( hp = 746 W ) | ||
| + | |||
| + | ==References== | ||
| + | <references/> | ||
[[Category:Physics]] | [[Category:Physics]] | ||
Revision as of 03:24, October 17, 2007
In physics, power refers to the rate of transfer of energy respect to time [1].
Mathematically, average power is expressed as:
P = W / Δt
Therefore, power at any instant can be determined by the equation:
P = limΔt->0 W / Δt = dW / dt
Since dW = F dx and v = dx / dt follows that:
P = F dx / dt = F v
The usual units for power are Watts ( W = J/s ) and horsepower ( hp = 746 W )
References
- ↑ Serway and Beichner, Physics For Scientists and Engineers, Fifth Edition