Foot-pound Per Second (ft⋅lbf/s)
About 1.3558 watts. A horsepower is 550 of these.
1 foot-pound per second = 1.355817948 watts (approximately).
About the foot-pound per second
Engineers in the English-speaking world measured work as force times distance, so a pound-force lifted through a foot became a foot-pound, and doing it each second gave the foot-pound per second. It is the base from which horsepower is built, since the imperial horsepower is defined as 550 foot-pounds per second, or 33,000 per minute, the figure fixed by James Watt and Matthew Boulton in 1783.
In SI terms one foot-pound per second is about 1.3558 watts, and NIST lists 1.355818 watts without marking it exact. The reverse is 1 watt equal to 0.7375621 foot-pounds per second. Multiplying 550 by 1.3558 gives about 745.7 watts, the usual value for a mechanical horsepower. The unit is rarely quoted on its own today, though it appears in older mechanics texts and in small-scale power estimates.
Sources: Wikipedia: Horsepower; Wikipedia: Watt; NIST SP 811, Appendix B.8
Foot-pound Per Second conversion chart
1 foot-pound per second expressed in every other power unit:
| Unit | 1 foot-pound per second |
|---|---|
| Watts | 1.355817948 |
| Kilowatts | 0.001355817948 |
| Horsepower | 0.001818181818 |
| Megawatts | 0.000001355817948 |
| Gigawatts | 1.355817948×10⁻⁹ |
| Metric Horsepower | 0.001843399392 |
| BTU Per Hour | 4.626242868 |
| Milliwatts | 1,355.817948 |
| Electrical Horsepower | 0.001817450333 |
| Tons Of Refrigeration | 0.000385520239 |
| Kilocalories Per Hour | 1.166573761 |
| Calories Per Second | 0.3240482668 |
| Ergs Per Second | 13,558,179.48 |
| Poncelets | 0.001382549544 |
More US & Imperial units
- horsepower (power)
- electrical horsepower (power)
- BTU per hour (power)
- ton of refrigeration (power)
- inch (length)
- foot (length)
- yard (length)
- mile (length)
- thou (length)
- league (length)
- furlong (length)
- chain (length)
- rod (length)
- link (length)
- hand (length)
- pound (weight & mass)
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