Joule vs. Erg — What's the Difference?

A joule is a unit of energy equal to the work done by a force of one newton moving an object one meter.

Due to its small size, an erg is practical in theoretical physics for energy calculations.

In terms of heat energy, one joule is the amount required to raise the temperature of a gram of water by 0.24 degrees Celsius.

Ergs measure work in a similar way to joules but on a much smaller scale.

Joules can also express kinetic energy,

An erg is a small unit of energy in the CGS system, suitable for microscopic energy scales.

Joules are used to measure electrical energy, such as kilowatt-hours converted to joules.

Ergs can also describe energy in terms of heat, especially in controlled physics experiments.

Joules are applicable in nutrition to describe food energy, often compared to calories.

Ergs are often used in astrophysics and particle physics calculations.

The joule ( jowl, jool; symbol: J) is a derived unit of energy in the International System of Units. It is equal to the energy transferred to (or work done on) an object when a force of one newton acts on that object in the direction of the force's motion through a distance of one metre (1 newton-metre or N⋅m).

The erg is a unit of energy equal to 10−7 joules (100 nJ). It originated in the centimetre–gram–second (CGS) system of units.

The International System unit of electrical, mechanical, and thermal energy, equal to the work done when a force of one newton acts through a distance of one meter, and also equal to the work done when a current of one ampere is passed through a resistance of one ohm for one second.

The centimeter-gram-second unit of energy or work equal to the work done by a force of one dyne acting over a distance of one centimeter.

In the International System of Units, the derived unit of energy, work and heat; the work required to exert a force of one newton for a distance of one metre. Equivalent to one watt of power for a duration of one second. Symbol: J

An extensive area of desert covered with shifting sand dunes.

A unit of work which is equal to 107 ergs (the unit of work in the C. G. S. system of units), and is equivalent to one watt-second, the energy expended in one second by an electric current of one ampere in a resistance of one ohm; also called the absolute joule. It is abbreviated J or j. The international joule is slightly larger, being 1.000167 times the absolute joule. The absolute joule is approximately equal to 0.737562 foot pounds, 0.239006 gram-calories (small calories), and 3.72506 x 10-7 horsepower-hours, and 0.000948451 B.t.u.

The unit of work or energy, being the amount of work done by a force of one dyne applied through a distance of one centimeter. Equal to 10⁻⁷ joules.

A unit of electrical energy equal to the work done when a current of one ampere passes through a resistance of one ohm for one second

(geomorphology) A large desert region of sand dunes with little or no vegetation, especially in the Sahara.

English physicist who established the mechanical theory of heat and discovered the first law of thermodynamics (1818-1889)

An ergometer.

To use an ergometer.

The unit of work or energy in the C. G. S. system, being the amount of work done by a dyne working through a distance of one centimeter; the amount of energy expended in moving a body one centimeter against a force of one dyne (981 dynes exert the same force as a one gram mass in the earth's gravitational field). One foot pound is equal to 13,560,000 ergs. The absolute Joule is equivalent to 107 ergs, which are equivalent to 0.2389 gram-calories at 15° C. See also mechanical equivalent of heat under equivalent.

A cgs unit of work or energy; the work done by a force of one dyne acting over a distance of one centimeter

Yes, converting joules to ergs is straightforward: 1 joule equals 10^7 ergs.

Both joules and ergs measure energy, but joules are part of the SI system and ergs are part of the CGS system, reflecting different scales and usage contexts.

Yes, joules are very relevant in everyday life, especially in measuring electrical energy usage and the caloric content of foods.

Ergs are typically taught in specialized physics courses, particularly those focusing on the CGS system and theoretical aspects of physics.

Ergs are more beneficial in theoretical and microscopic physics, where dealing with extremely small energy quantities is common.

A scientist might choose ergs for precision in small-scale energy calculations, typical in fields like quantum mechanics and particle physics.

Practical applications of ergs are mostly limited to scientific research, such as in studies of electromagnetic fields and radiation.

Joules are used to express the energy content in food, where 1 dietary calorie is approximately 4184 joules.

In scientific research, ergs are crucial for measuring very small energy levels, such as in particle physics and astrophysics.

Industries such as electrical power, mechanical engineering, and health (in terms of dietary energy) heavily rely on the use of joules.

The adoption of joules followed developments in mechanical and electrical engineering, while ergs were adopted due to their utility in early 20th-century physics.

Joules directly impact daily technology in aspects like power consumption in household appliances and energy efficiency ratings.

Joules help in calculating the energy efficiency and carbon footprint of various processes, while ergs might be used in modeling microscopic environmental interactions.

A basic understanding of physics and mathematics is needed to grasp the concepts of joules and ergs, with advanced studies required for deeper understanding, especially for ergs.

Yes, calorimeters measure energy in joules for heat changes, while specialized sensors in physics experiments might measure energy in ergs.