The title of this article is ambiguous. Further meanings are listed under
Erg .
Physical unit

Unit name 
erg

Unit symbol

${\ displaystyle \ mathrm {erg}}$

Physical quantity (s)

Energy (e.g. work , internal energy , heat )

Formula symbol

${\ displaystyle E; \, W; \, U; \, Q}$

dimension

${\ displaystyle {\ mathsf {M \; L ^ {2} \; T ^ { 2}}}}$

system

CGS system of units

In SI units

${\ displaystyle \ mathrm {1 \, erg = 0 {,} 1 \; \ mu J}}$ ${\ displaystyle \ mathrm {= 1 \ cdot 10 ^ { 7} \; {\ frac {kg \, m ^ {2}} {s ^ {2}}}}}$

In CGS units

${\ displaystyle \ mathrm {1 \, erg = 1 \; {\ frac {cm ^ {2} \, g} {s ^ {2}}}}}$

Derived from

dyn , centimeters

The erg ( unit symbol : erg; from Greek ἔργον , ergon , work ) is a unit of measurement in the CGS system of units for energy . The unit is widely used in astrophysics and sometimes mechanics .
Except for a power of ten, the erg corresponds to the unit joule , which is common in the MBS based International System of Units (SI) :
 ${\ displaystyle {\ begin {aligned} 1 \ \ mathrm {erg} & = \ mathrm {0 {,} 1 \ \ mu J = 1 \ cdot 10 ^ { 7} J} \\\ Leftrightarrow 10 ^ {7 } \ \ mathrm {erg} & = 1 \ \ mathrm {J} \ end {aligned}}}$
Considering the dimensions of the energy provides a dimension
energy 
= Force x length


= Mass · acceleration · length


= Mass (length / time) ^{2}

and therefore the unit in the cgs system
 ${\ displaystyle {\ begin {aligned} 1 \ \ mathrm {erg} & = \ mathrm {1 \ g \ cdot \ left ({\ frac {cm} {s}} \ right) ^ {2}} \\ & = \ mathrm {1 \ dyn \ cdot \ cm} \ end {aligned}}}$
with the Dyn .
In Germany, the Erg is no longer a legal unit since January 1, 1978 .
See also