Search results
Results from the WOW.Com Content Network
List of orders of magnitude for energy; Factor (joules) SI prefix Value Item 10 −34: 6.626 × 10 −34 J: Energy of a photon with a frequency of 1 hertz. [1]8 × 10 −34 J: Average kinetic energy of translational motion of a molecule at the lowest temperature reached (38 picokelvin [2] as of 2021)
The joule (/ dʒ uː l / JOOL, or / dʒ aʊ l / JOWL; symbol: J) is the unit of energy in the International System of Units (SI). [1] It is equal to the amount of work done when a force of one newton displaces a mass through a distance of one metre in the direction of that force.
Inevitably, the powers of ten reappeared in other contexts, but the effect was to make the familiar joule and watt the units of work and power respectively. The ampere-turn system is constructed in a similar way by considering magnetomotive force and magnetic field strength to be electrical quantities and rationalizing the system by dividing ...
Both energy and torque can be expressed as a product of a force vector with a displacement vector (hence pounds and feet); energy is the scalar product of the two, and torque is the vector product. Although calling the torque unit "pound-foot" has been academically suggested, both are still commonly called "foot-pound" in colloquial usage.
[4]: 2 For example, using metre per second is coherent in a system that uses metre for length and second for time, but kilometre per hour is not coherent. The principle of coherence was successfully used to define a number of units of measure based on the CGS, including the erg for energy , the dyne for force , the barye for pressure , the ...
In the SI system (expressing the ratio E / m in joules per kilogram using the value of c in metres per second): [35] E / m = c 2 = (299 792 458 m/s) 2 = 89 875 517 873 681 764 J/kg (≈ 9.0 × 10 16 joules per kilogram). So the energy equivalent of one kilogram of mass is 89.9 petajoules; 25.0 billion kilowatt-hours (≈ 25,000 ...
The second is readily determined from the Earth's rotation period. Unlike other units, time multiples are not decimal. A second is 1 / 60 of a minute, which is 1 / 60 of an hour, which is 1 / 24 of a day, so a second is 1 / 86 400 of a day.
A Assuming an altitude of 194 metres above mean sea level (the worldwide median altitude of human habitation), an indoor temperature of 23 °C, a dewpoint of 9 °C (40.85% relative humidity), and 760 mmHg sea level–corrected barometric pressure (molar water vapor content = 1.16%).