Physical quantity representing energy content per unit mass
Specific energy
Common symbols
SI unit
J/kg
Other units
kcal/g, W⋅h/kg, kW⋅h/kg, Btu/lb
In SI base units
m2⋅s−2
Intensive?
Yes
Derivations from other quantities
Dimension
Specific energy or massic energy is energy per unit mass. It is also sometimes called gravimetric energy density, which is not to be confused with energy density, which is defined as energy per unit volume. It is used to quantify, for example, stored heat and other thermodynamic properties of substances such as specific internal energy, specific enthalpy, specific Gibbs free energy, and specific Helmholtz free energy. It may also be used for the kinetic energy or potential energy of a body. Specific energy is an intensive property, whereas energy and mass are extensive properties.
The SI unit for specific energy is the joule per kilogram (J/kg). Other units still in use worldwide in some contexts are the kilocalorie per gram (Cal/g or kcal/g), mostly in food-related topics, and watt hours per kilogram in the field of batteries. In some countries the Imperial unit BTU per pound (Btu/lb) is used in some engineering and applied technical fields.[1]
The concept of specific energy is related to but distinct from the notion of molar energy in chemistry, that is energy per mole of a substance, which uses units such as joules per mole, or the older but still widely used calories per mole.[2]
^
Kenneth E. Heselton (2004), "Boiler Operator's Handbook". Fairmont Press, 405 pages. ISBN 0881734357
^
Jerzy Leszczynski (2011), "Handbook of Computational Chemistry". Springer, 1430 pages. ISBN 940070710X
Specificenergy or massic energy is energy per unit mass. It is also sometimes called gravimetric energy density, which is not to be confused with energy...
the gravitational two-body problem, the specific orbital energy ε {\displaystyle \varepsilon } (or vis-viva energy) of two orbiting bodies is the constant...
Specificenergy density may refer to: Energy density, energy per unit volume Specificenergy, energy per unit mass This disambiguation page lists articles...
Aircraft-specificenergy is a form of specificenergy applied to aircraft and missile trajectory analysis. It represents the combined kinetic and potential...
thermometer, relating the latter to thermal energy. A specific latent heat (L) expresses the amount of energy in the form of heat (Q) required to completely...
amount of heat (known as the lattice energy) to the surroundings. Although heat is "wasted" energy for a specificenergy transfer (see: waste heat), it can...
of energy efficiency, which can decrease as specific impulse increases, since propulsion systems that give high specific impulse require high energy to...
Specific absorption rate (SAR) is a measure of the rate at which energy is absorbed per unit mass by a human body when exposed to a radio frequency (RF)...
lithium nickel manganese cobalt oxides (NMC) type batteries in 2028. The specificenergy of LFP batteries is lower than that of other common lithium ion battery...
Specific mechanical energy is the mechanical energy of an object per unit of mass. Similar to mechanical energy, the specific mechanical energy of an...
The internal energy of a thermodynamic system is the energy contained within it, measured as the quantity of energy necessary to bring the system from...
called specificenergy or gravimetric energy density. Often only the useful or extractable energy is measured, which is to say that inaccessible energy (such...
latter form is rarely used. Specific strength has the same units as specificenergy, and is related to the maximum specificenergy of rotation that an object...
energy, called energy levels. This contrasts with classical particles, which can have any amount of energy. The term is commonly used for the energy levels...
comparing the energy density of various energy-storing devices. On such a chart the values of specificenergy (in W·h/kg) are plotted versus specific power (in...
exchanges and computer data centers. Batteries have much lower specificenergy (energy per unit mass) than common fuels such as gasoline. In automobiles...
high specificenergy (100–130 W·h/kg, or 360–500 kJ/kg), and large maximum power output. The energy efficiency (ratio of energy out per energy in) of...
mass Specificenergy, defined as energy per unit mass Specific internal energy, internal energy per unit mass Specific kinetic energy, kinetic energy of...
In surface science, surface energy (also interfacial free energy or surface free energy) quantifies the disruption of intermolecular bonds that occurs...
qualifier "specific" in front of an extensive property often indicates an intensive property derived from it.) The injection of heat energy into a substance...
specific surface area. In 1957 H. Becker developed a "Low voltage electrolytic capacitor with porous carbon electrodes". He believed that the energy was...
pursuit, with the physics of managing the aircraft's energy-to-mass ratio, called its specificenergy. Maneuvers are used to gain a better angular position...
In physics, potential energy is the energy held by an object because of its position relative to other objects, stresses within itself, its electric charge...
astrodynamics, the characteristic energy ( C 3 {\displaystyle C_{3}} ) is a measure of the excess specificenergy over that required to just barely escape...
The law of specific nerve energies, first proposed by Johannes Peter Müller in 1835, is that the nature of perception is defined by the pathway over which...
(gel) polymers form this electrolyte. These batteries provide higher specificenergy than other lithium battery types and are used in applications where...
Global Information
