ENERGY, WORK AND POWER UNITS CONVERSION

DEFINITIONS, ONLINE CALCULATORS, EQUATIONS

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Energy in general is defined as the capacity for doing work. Power (P) is the rate of doing work or the rate of using energy: P=Work/t=Energy/t, where t is time. Although casually the terms energy and power are often used interchangeably we see technically they have different meanings.

Energy comes in many forms, such as heat, motion, gravitational, and electrical. The SI unit of energy and work (which are numerically the same) is the joule. By definition, work done by a constant force F when it moves an object by distance L in the direction of force is Work=F×L. A joule (J) is the work done by a force of one newton for a distance of one meter. This unit is usually used in physics. For different types of energy other physical units are also used. For example, the British Thermal Unit (Btu) is often used to measure the heat energy or compare fuels. One Btu is the energy needed to heat one pound of water one degree F.

The SI derived unit of power is watt (W). Watt is power required to produce or use of one joule of energy per second.

In an uniform electric field with voltage V over distance L, the force acting on a change Q is equal to F=V/L×Q (particularly, in the field of 1 volt/meter, force of 1 newton is acting on one coulomb charge). Substituting this into the above general expression of power gives the equation for power required to move a charge Q in an electric field: P = F×L/t = V×Q/t. The rate of charge flow Q/t is called electric current I. Replacing Q/t with I in the above expression yields a familiar formula for instantaneous value of electric power: P=V×I. For the mathematics of electric energy, power and power factor, see Electric power primer.



POWER UNIT CONVERSION CALCULATOR


watt [W]:
kilowatt [kW]:
megawatt [MW]:
milliwatt [mW]:
horsepower [hp, hp (UK)]:
horsepower (550 ft*lbf/s):
horsepower (metric):
horsepower (boiler):
Btu (IT)/hour [Btu/h]:
Btu (IT)/second [Btu/s]:
Btu (th)/hour [Btu (th)/h]:
ton (refrigeration):
kilocalorie (IT)/hour:
calorie (IT)/second:
foot pound-force/hour:
foot pound-force/second:
pound-foot/hour:
pound-foot/second:
erg/second [erg/s]:
volt ampere [V*A]:
newton meter/second:
joule/second [J/s]:
kilojoule/hour [kJ/h]:
power and energy conversion factors provided by unitconversion.org




Notes: IT- International Table
            th- thermochemical unit

ENERGY UNIT CONVERSION CALCULATOR


joule [J]:
kilojoule [kJ]:
electron-volt [eV]:
erg:
kilowatt-hour [kW*h]:
watt-hour [W*h]:
watt-second [W*s]:
newton meter [N*m]:
horsepower hour [hp*h]:
horsepower (metric) hour:
kilocalorie (IT) [kcal (IT)]:
kilocalorie (th) [kcal (th)]:
calorie (IT) [cal (IT), cal]:
calorie (th) [cal (th)]:
calorie (nutritional):
Btu (IT) [Btu (IT), Btu]:
Btu (th) [Btu (th)]:
ton-hour (refrigeration):
ton (explosives):
dyne centimeter:
gram-force centimeter:
kilogram-force meter:
pound-force foot [lbf*ft]:
pound-force inch [lbf*in]:
ounce-force inch [ozf*in]:
foot-pound [ft*lbf]:
inch-pound [in*lbf]:
inch-ounce [in*ozf]:
therm:
therm (US):
Hartree energy:
Rydberg constant:


© 2007 Lazar Rozenblat