Search results

In photography, exposure is the amount of light per unit area (the image plane illuminance times the exposure time) reaching a photographic film, as ... more

Sound power or acoustic power is a measure of sound energy per time unit. It is the power of the sound force on a surface of the medium of propagation of ... more

The free-fall time is the characteristic time that would take a body to collapse under its own gravitational attraction, if no other forces existed to ... more

The Rydberg formula is used in atomic physics to describe the wavelengths of spectral lines of many chemical elements. It was formulated by the Swedish ... more

In physics, circular motion is a movement of an object along the circumference of a circle or rotation along a circular path. It can be uniform, with ... more

In physics, circular motion is a movement of an object along the circumference of a circle or rotation along a circular path. It can be uniform, with ... more

The speed of light in vacuum is the speed at which all massless particles and changes of the associated fields (including electromagnetic radiation such as ... more

A polarizer or polariser is an optical filter that passes light of a specific polarization and blocks waves of other polarizations.
When a perfect ... more

In plasma physics, an Alfvén wave, named after Hannes Alfvén, is a type of magnetohydrodynamic wave in which ions oscillate in response to a restoring ... more

A linear equation is an algebraic equation in which each term is either a constant or the product of a constant and (the first power of) a single variable. ... more