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Energy; system unit code (alternative) symbol or abbrev. notes sample default conversion combinations SI: yottajoule: YJ YJ 1.0 YJ (2.8 × 10 17 kWh) zettajoule: ZJ ZJ 1.0 ZJ (2.8 × 10 14 kWh)
A kilowatt-hour (unit symbol: kW⋅h or kW h; commonly written as kWh) is a non-SI unit of energy equal to 3.6 megajoules (MJ) in SI units, which is the energy delivered by one kilowatt of power for one hour. Kilowatt-hours are a common billing unit for electrical energy supplied by electric utilities.
If a comet with this speed fell to the Earth it would gain another 63 MJ/kg, yielding a total of 2655 MJ/kg with a speed of 72.9 km/s. Since the equator is moving at about 0.5 km/s, the impact speed has an upper limit of 73.4 km/s, giving an upper limit for the specific energy of a comet hitting the Earth of about 2690 MJ/kg.
Energy densities table Storage type Specific energy (MJ/kg) Energy density (MJ/L) Peak recovery efficiency % Practical recovery efficiency % Arbitrary Antimatter ...
A unit of electrical energy, particularly for utility bills, is the kilowatt-hour (kWh); [3] one kilowatt-hour is equivalent to 3.6 megajoules. Electricity usage is often given in units of kilowatt-hours per year or other periods. [4] This is a measurement of average power consumption, meaning the average rate at which energy is transferred ...
Specific energy is energy per unit mass, which is used to describe the chemical energy content of a fuel, expressed in SI units as joule per kilogram (J/kg) or equivalent units. [1] Energy density is the amount of chemical energy per unit volume of the fuel, expressed in SI units as joule per litre (J/L) or equivalent units. [2]
= 1 kWh (kilowatt-hour) (used for electricity) [59] 4.2×10 6 J: Energy released by explosion of 1 kilogram of TNT [59] [99] 6.1×10 6 J Kinetic energy of the 4 kg tungsten APFSDS penetrator after being fired from a 120mm KE-W A1 cartridge with a nominal muzzle velocity of 1740 m/s. [113] [114] 8.4×10 6 J
A typical turbocharged V8 diesel engine might have an engine power of 250 kW (340 hp) and a mass of 380 kg (840 lb), [1] giving it a power-to-weight ratio of 0.65 kW/kg (0.40 hp/lb). Examples of high power-to-weight ratios can often be found in turbines.