Units of energy: Difference between revisions

Latest revision as of 22:10, 16 February 2025

Units of Energy[edit]

Units of energy are measurements used to quantify the amount of energy. Energy is a fundamental concept in physics and is essential in various fields such as engineering, chemistry, and environmental science. Different units are used depending on the context and the scale of energy being measured.

Common Units of Energy[edit]

Joule[edit]

The joule (symbol: J) is the SI unit of energy. It is defined as the amount of energy transferred when a force of one newton is applied over a distance of one meter. The joule is named after the English physicist James Prescott Joule.

Calorie[edit]

The calorie (symbol: cal) is a unit of energy commonly used in nutrition. It is defined as the amount of energy needed to raise the temperature of one gram of water by one degree Celsius. The kilocalorie (kcal), often referred to as the "Calorie" with a capital C, is used to express the energy content in food.

Kilowatt-hour[edit]

The kilowatt-hour (symbol: kWh) is a unit of energy commonly used to measure electrical energy consumption. It is defined as the amount of energy consumed by a device with a power of one kilowatt running for one hour.

Electronvolt[edit]

The electronvolt (symbol: eV) is a unit of energy commonly used in the field of particle physics. It is defined as the amount of kinetic energy gained by an electron when it is accelerated through an electric potential difference of one volt.

Conversion Between Units[edit]

Energy units can be converted from one to another using conversion factors. For example, 1 calorie is approximately equal to 4.184 joules, and 1 kilowatt-hour is equal to 3.6 million joules.

Related Pages[edit]

References[edit]

"Energy Units." International System of Units. Retrieved from [1].
"Conversion of Units." NIST. Retrieved from [2].

Log10 ratios between energy units

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-'''Units of Energy''' are standardized measures used to quantify the amount of [[energy]] in a physical system. Energy can be defined as the capacity to do [[work (physics)|work]] or to cause change. The units of energy are diverse and can be classified based on the system of measurement, such as the [[International System of Units|SI system]], the [[British Imperial System|Imperial system]], and others.
+== Units of Energy ==
-== SI Units of Energy ==
+Units of energy are measurements used to quantify the amount of energy. Energy is a fundamental concept in physics and is essential in various fields such as engineering, chemistry, and environmental science. Different units are used depending on the context and the scale of energy being measured.
-The standard unit of energy in the International System of Units (SI) is the [[joule (unit)|joule]] (J). It is defined as the energy transferred when a force of one [[newton (unit)|newton]] moves an object over a distance of one [[metre]]. Other SI units of energy include the [[watt-hour]] (Wh), [[kilowatt-hour]] (kWh), and [[megajoule]] (MJ).
+== Common Units of Energy ==
-== Non-SI Units of Energy ==
+=== Joule ===
+The [[joule]] (symbol: J) is the SI unit of energy. It is defined as the amount of energy transferred when a force of one [[newton]] is applied over a distance of one [[meter]]. The joule is named after the English physicist [[James Prescott Joule]].
-Non-SI units of energy are also commonly used in various fields. These include the [[calorie]] (cal), which is often used in nutrition, and the [[British thermal unit]] (BTU), which is commonly used in heating and cooling industries. The [[electronvolt]] (eV) is used in atomic and nuclear physics.
+=== Calorie ===
+The [[calorie]] (symbol: cal) is a unit of energy commonly used in nutrition. It is defined as the amount of energy needed to raise the temperature of one gram of water by one degree Celsius. The kilocalorie (kcal), often referred to as the "Calorie" with a capital C, is used to express the energy content in food.
-== Energy Equivalents ==
+=== Kilowatt-hour ===
+The [[kilowatt-hour]] (symbol: kWh) is a unit of energy commonly used to measure electrical energy consumption. It is defined as the amount of energy consumed by a device with a power of one [[kilowatt]] running for one hour.
-Energy can also be expressed in terms of equivalents. For example, one joule is equivalent to approximately 0.239 calories, or 9.48 x 10^-4 BTUs. Similarly, one calorie is equivalent to approximately 4.184 joules, or 3.97 x 10^-3 BTUs.
+=== Electronvolt ===
+The [[electronvolt]] (symbol: eV) is a unit of energy commonly used in the field of particle physics. It is defined as the amount of kinetic energy gained by an electron when it is accelerated through an electric potential difference of one volt.
-== Energy Conversion ==
+== Conversion Between Units ==
+Energy units can be converted from one to another using conversion factors. For example, 1 calorie is approximately equal to 4.184 joules, and 1 kilowatt-hour is equal to 3.6 million joules.
-Energy conversion involves changing one form of energy into another. For example, a [[power plant]] converts chemical energy in fuel into electrical energy. The efficiency of these conversions can vary, and is often expressed as a percentage of the total energy input.
+[[File:Log10 ratios between energy units.png|thumb|right|Logarithmic scale of energy units]]
-== See Also ==
+== Related Pages ==
 * [[Energy]]
+* [[Power (physics)]]
 * [[Work (physics)]]
-* [[Power (physics)]]
+* [[Thermodynamics]]
-* [[Energy conversion]]
-* [[Energy conservation]]
-* [[Energy efficiency]]
 == References ==
+* "Energy Units." [[International System of Units]]. Retrieved from [https://www.bipm.org/en/measurement-units/].
+* "Conversion of Units." [[NIST]]. Retrieved from [https://www.nist.gov/pml/weights-and-measures].
-{{reflist}}
+{{Physics}}
+{{Energy}}
 [[Category:Units of energy]]
-[[Category:Physics]]
+<gallery>
-[[Category:Energy]]
+File:Log10_ratios_between_energy_units.png|Log10 ratios between energy units
-{{physics-stub}}
+</gallery>