| horsepower-hour | |
|---|---|
| Unit of | Energy |
| Symbol | hp⋅h |
| Conversions | |
| 1 hp⋅h in ... | ... is equal to ... |
| SI units | 2.685 MJ |
| CGS units | 2.685×1013 erg |
| English Engineering Units | 1.98×106 ft⋅lbf |
A horsepower-hour (symbol: hp⋅h) is an outdated unit of energy, not used in the International System of Units. The unit represents an amount of work a horse is supposed capable of delivering during an hour (1 horsepower integrated over a time interval of an hour). Based on differences in the definition of what constitutes the "power of a horse", a horsepower-hour differs slightly from the German Pferdestärkenstunde (PSh):
- 1.014 PSh = 1 hp⋅h = 1,980,000 lbf⋅ft = 0.7457 kW⋅h.
- 1 PSh = 0.73549875 kW⋅h = 2647.7955 kJ (exactly by definition)
The horsepower-hour is still used in the railroad industry when sharing motive power (locomotives). For example, if Railroad A borrows a 2,500 horsepower locomotive from Railroad B and operates it for twelve hours, Railroad A owes a debt of (2,500 hp × 12 h) = 30,000 hp⋅h. Railroad A may repay the debt by loaning Railroad B a 3,000 horsepower locomotive for ten hours.[1]
References[edit]
- ^ "Trains Magazine - Ask Trains from December 2007". Archived from the original on 2008-12-04. Retrieved 2009-05-25.
Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction