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Continuous charge distribution. The volume charge density ρ is the amount of charge per unit volume (cube), surface charge density σ is amount per unit surface area (circle) with outward unit normal n̂, d is the dipole moment between two point charges, the volume density of these is the polarization density P.
For example, the photons emitted by a radio station broadcast at the frequency ν = 100 MHz, have an energy content of νh = (1 × 10 8) × (6.6 × 10 −34) = 6.6 × 10 −26 J, where h is the Planck constant. The wavelength of the station is λ = c/ν = 3 m, so that λ/(2π) = 48 cm and the volume is 0.109 m 3.
Position vectors r and r′ used in the calculation. The starting point is Maxwell's equations in the potential formulation using the Lorenz gauge: =, = where φ(r, t) is the electric potential and A(r, t) is the magnetic vector potential, for an arbitrary source of charge density ρ(r, t) and current density J(r, t), and is the D'Alembert operator. [2]
The quantum potential or quantum potentiality is a central concept of the de Broglie–Bohm formulation of quantum mechanics, introduced by David Bohm in 1952.. Initially presented under the name quantum-mechanical potential, subsequently quantum potential, it was later elaborated upon by Bohm and Basil Hiley in its interpretation as an information potential which acts on a quantum particle.
More Magic Triangle image mnemonics in the style of a cheat-sheet for high-school physics – in the SVG file, hover over a symbol for its meaning and formula. This is a categorized list of physics mnemonics .
In classical mechanics, the central-force problem is to determine the motion of a particle in a single central potential field.A central force is a force (possibly negative) that points from the particle directly towards a fixed point in space, the center, and whose magnitude only depends on the distance of the object to the center.
In the general time-independent case, the dynamics of a particle in a spherically symmetric potential are governed by a Hamiltonian of the following form: ^ = ^ + Here, is the mass of the particle, ^ is the momentum operator, and the potential () depends only on the vector magnitude of the position vector, that is, the radial distance from the ...
The Lorentz reciprocity theorem is simply a reflection of the fact that the linear operator ^ relating and at a fixed frequency (in linear media): = ^ where ^ [()] is usually a symmetric operator under the "inner product" (,) = for vector fields and . [8] (Technically, this unconjugated form is not a true inner product because it is not ...