# Power

 value unit J/s ijoule per second W iwattSI base unit of powerIn mechanical terms, one watt equals about 0.001 341 02 horsepower (hp) or 0.737 562 foot-pound per second (lbf/s). In electrical terms, one watt is the power produced by a current of one ampere flowing through an electric potential of one volt. kW ikilowatt MW imegawatt kJ/hr ikilojoule per hour kgf • m/s ikilogram force meter per second cal/s icalorie per second cal/hr icalorie per hour BTU/s iBritish thermal units per second BTU/hr iBritish thermal units per hour Ton (RT) itonsUnit of power used in refrigeration engineering. One ton of refrigeration is intended to be the power required to freeze one short ton of water at 0?C in 24 hours. This is assumed to be exactly 12 000 Btu per hour pk (Metric hp) imetric horse powerUnit of power, defined to be the power required to raise a mass of 75 kilograms at a velocity of 1 meter per second. This is approximately 735.499 watts or 0.986 32 horsepower hp ihorse powerUnit of power representing the power exerted by a horse in pulling ehp ielectric horse powerUnit of power, equal to exactly 746 watts (550.221 foot pounds per second) bhp iboiler horse powerThe boiler horsepower is defined to be the power required to convert 30 pounds (13.61 kilograms) per hour of water at 100 ?F (37.78 ?C) to saturated steam at a pressure of 70 pounds per square inch gauge (482.6 kilopascals gauge). This power, about 33 471 Btu per hour or 9.8095 kilowatts lbf • ft/s ipound force foot per second1 hose power = exactly 550 lbf • ft/s