joule

(noun)

The derived SI unit of energy, work, and heat; equal to the energy of one watt of power for a duration of one second; symbol: J.

Related Terms

Examples of joule in the following topics:

  • Nuclear Binding Energy and Mass Defect

    • Once this energy, which is a quantity of joules for one nucleus, is known, it can be scaled into per-nucleon and per-mole quantities.
    • To convert to joules/mole, simply multiply by Avogadro's number.
    • To convert to joules per nucleon, simply divide by the number of nucleons.
    • $2.7843\times10^{-10}\frac{Joules}{atom}\ \times \frac {6.02\times10^{23}\ atoms}{mole}\times \frac{1\ kJ}{1000\ joules} =$ 1.6762 x 1011$\frac{kJ}{mole}$

  • Heat as Energy Transfer

    • Owing to the fact that heat is a form of energy, it has the SI unit of joule (J).
    • In some engineering fields, the British Thermal Unit (BTU), equal to about 1.055 kilo-joules, is widely used.
    • James Prescott Joule (1818–1889) performed many experiments to establish the mechanical equivalent of heat—the work needed to produce the same effects as heat transfer.
    • Joule demonstrated that the temperature of a system can be increased by stirring.

  • Force in the Direction of Displacement

    • The SI unit of work is the newton-meter or joule (J).
    • Kinetic energy - and all forms of energy - have units of joules (J).

  • The Electron-Volt

    • As such, it is equal to the product of one volt (1 J/C) and one elementary charge, giving it a value in joules approximately equal to 1.602×10-19 J.
    • To convert to Kelvins, simply divide the value of 1 eV (in Joules) by the Boltzmann constant (1.3806505(24)×10-23 J/K).

  • Electric Potential Energy and Potential Difference

    • It is measured in joules and depends on the positioning of charged particles relative to one another, as well as the magnitude of their respective charges.
    • It is denoted by ∆V and has units of volts, or joules per Coulomb.

  • Heat and Work

    • The units of heat are therefore the units of energy, or joules (J).
    • Like heat, the unit measurement for work is joules (J).

  • Free Energy and Cell Potential

    • One volt is $1\frac {Joule}{Coulomb}$.
    • $\Delta G^o = -2 \ moles\ e^- \times 96485\frac {Coulombs}{mole} \times 0.12 \frac {Joules}{Coulomb}$

  • Energy Usage

    • We are of course very familiar with the SI unit of energy, the joule.
    • We can parse out the conversion from kilowatt-hours to joules in this way: 1 W = 1 J/s and a kilowatt is 1000 W while one hour is 3,600 seconds, so 1 kWh is (1000 J/s)(3600 s)=3,600,000 joules.

  • Bond Energy

    • The SI unit of energy is the joule, symbol J.

  • Gravity

    • where PE = potential energy measured in joules (J), m = mass of the object (measured in kg), and h = perpendicular height from the reference point (measured in m); g = gravitational acceleration (9.8m/s2).