enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Gas constant - Wikipedia

    en.wikipedia.org/wiki/Gas_constant

    The molar gas constant (also known as the gas constant, universal gas constant, or ideal gas constant) is denoted by the symbol R or R. It is the molar equivalent to the Boltzmann constant, expressed in units of energy per temperature increment per amount of substance, rather than energy per temperature increment per particle.

  3. Coefficient of determination - Wikipedia

    en.wikipedia.org/wiki/Coefficient_of_determination

    In statistics, the coefficient of determination, denoted R2 or r2 and pronounced "R squared", is the proportion of the variation in the dependent variable that is predictable from the independent variable (s). It is a statistic used in the context of statistical models whose main purpose is either the prediction of future outcomes or the ...

  4. Area of a circle - Wikipedia

    en.wikipedia.org/wiki/Area_of_a_circle

    So the divergence of r is equal to two, and hence the area of a disc D is equal to A = 1 2 ∬ D div ⁡ r d A . {\displaystyle A={\frac {1}{2}}\iint _{D}\operatorname {div} \mathbf {r} \,dA.} By Green's theorem, this is the same as the outward flux of r across the circle bounding D :

  5. Ideal gas law - Wikipedia

    en.wikipedia.org/wiki/Ideal_gas_law

    This form of the ideal gas law is very useful because it links pressure, density, and temperature in a unique formula independent of the quantity of the considered gas. Alternatively, the law may be written in terms of the specific volume v, the reciprocal of density, as. It is common, especially in engineering and meteorological applications ...

  6. R-value (insulation) - Wikipedia

    en.wikipedia.org/wiki/R-value_(insulation)

    The R-value (in K ⋅ m 2/ W) is a measure of how well a two-dimensional barrier, such as a layer of insulation, a window or a complete wall or ceiling, resists the conductive [2] flow of heat, in the context of construction. [3]. R-value is the temperature difference per unit of heat flux needed to sustain one unit of heat flux between the ...

  7. Ohm's law - Wikipedia

    en.wikipedia.org/wiki/Ohm's_law

    Ohm's law states that the electric current through a conductor between two points is directly proportional to the voltage across the two points. Introducing the constant of proportionality, the resistance, [1] one arrives at the three mathematical equations used to describe this relationship: [2] where I is the current through the conductor, V ...

  8. Roentgen (unit) - Wikipedia

    en.wikipedia.org/wiki/Roentgen_(unit)

    2.58 × 10−4 A ⋅ s / kg. The roentgen or röntgen (/ ˈrɛntɡən, - dʒən, ˈrʌnt -/; [2] symbol R) is a legacy unit of measurement for the exposure of X-rays and gamma rays, and is defined as the electric charge freed by such radiation in a specified volume of air divided by the mass of that air (statcoulomb per kilogram).

  9. Equilibrium constant - Wikipedia

    en.wikipedia.org/wiki/Equilibrium_constant

    Equilibrium constant. The equilibrium constant of a chemical reaction is the value of its reaction quotient at chemical equilibrium, a state approached by a dynamic chemical system after sufficient time has elapsed at which its composition has no measurable tendency towards further change. For a given set of reaction conditions, the equilibrium ...