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> |
| − | <ref>Serway and Beichner, ''Physics For Scientists and Engineers'', Fifth Edition</ref> | ||
Mathematically, average power is expressed as: | Mathematically, average power is expressed as: | ||
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Since d''W'' = [[Force|F]] d[[distance|x]] and [[Velocity|v]] = dx / dt follows that: | Since d''W'' = [[Force|F]] d[[distance|x]] and [[Velocity|v]] = dx / dt follows that: | ||
| − | P = F dx / dt = F v | + | P = F · dx / dt = F · v |
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 ) | ||
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[[Category:Physics]] | [[Category:Physics]] | ||
| + | [[Category:Mechanics]] | ||
Latest revision as of 15:42, June 29, 2016
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