Entropy

A measure of the disorder or randomness in a system.

Carnot Engine Efficiency

Efficiency equals 1 minus cold reservoir temperature over hot reservoir temperature (e=1-Tc/Th).

Energy Stored in a Capacitor

Energy equals one half capacitance times voltage squared (U=1/2CV^2).

Boyle's Law

For a fixed amount of gas at constant temperature, pressure inversely proportional to volume (P1V1=P2V2).

Archimedes' Principle

The upward buoyant force on an object immersed in fluid is equal to the weight of the fluid displaced.

Electric Potential Energy

Electric potential energy equals charge times electric potential (U=qV).

Conservation of Mechanical Energy

In a closed system, the sum of kinetic and potential energy remains constant.

Conservation of Momentum

In a closed system, total momentum before equals total momentum after an event.

De Broglie Wavelength

A particle's wavelength is inversely proportional to its momentum (λ=h/p).

Avogadro's Law

Equal volumes of gases at the same temperature and pressure contain equal numbers of molecules.

Charles's Law

For a fixed amount of gas at constant pressure, volume directly proportional to temperature (V1/T1=V2/T2).

Brewster's Angle

The angle of incidence at which light with a particular polarization is perfectly transmitted through a transparent dielectric surface, with no reflection.

Coulomb's Law

Electrostatic force equals k times charge1 times charge2 divided by distance squared (Fe=k(q1q2)/r^2).

Compton Scattering

The increase in wavelength (and decrease in energy) of X-rays or gamma rays when scattered.

Critical Angle

The angle of incidence above which total internal reflection occurs.

Conservation of Angular Momentum

Angular momentum remains constant if no external torques act on the system.

Capacitance Formula

Capacitance equals charge divided by voltage (C=Q/V).

Biot-Savart Law

Calculates magnetic field produced by a current-carrying wire.

Doppler Effect

Change in frequency or wavelength of a wave in relation to an observer moving relative to the wave source.

Coulomb’s Law (Electric Fields)

Electric force between charged objects depends on the distance between the objects and the magnitude of the charges.

Continuity Equation for Fluids

Area times velocity remains constant (A1v1=A2v2).

Angular Momentum

Angular momentum equals moment of inertia times angular velocity (L=Iω).

Ampere’s Law

The magnetic field in space around an electric current is proportional to the electric current.

Bernoulli’s Equation

Pressure plus one half density times velocity squared plus density times gravity times height is constant.

Black Body Radiation

The electromagnetic radiation emitted by a body in thermal equilibrium.