Schrödinger Equation

— fundamental equation of quantum mechanics, which describes the dynamic behavior of a quantum system in time and space. S. e. is: $$\operatorname{th} \frac{\partial \psi}{\partial t} \hat{H} \psi$$ where $\hat{H}$ — Hamilton operator (see. Hamiltonian) $\psi$ — wave function, $h=\dfrac{h}{2 \pi}$, $h$ — Planckn constant. S. e. stationary (time-independent) states is: $$\hat{H} \psi_{n}=E_{n} \psi_{n}$$ and determines the eigenvalues $E_{n}$ operator $\hat{H}$ and the corresponding eigenfunctions $\psi_{n}$.

Width of the Spectral Line

— size frequency interval $\Delta \nu$, characterizing as monochromatic radiation of atoms, molecules and other quantum systems. Natural W.of the s.l. associated with finite duration single act atomic radiation $\left(\tau \sim 10^{-8} \mathrm{s}\right)$ and equal $\Delta \nu_{\mathrm{e c m}} \sim 10^{8} c^{-1}$. The impact of electric and magnetic fields and thermal motion of atoms and molecules at different speeds relative to the measuring device (see. Doppler effect) lead to increased spectral lines (see.

Width Levels

— a measure of the uncertainty of the quantum state of energy associated with the uncertainty relation for energy and time: $$\Delta E>\frac{h}{\tau}$$ where $h=\dfrac{h}{2 \pi}$, $h$ — Planck constant, $\tau$ — the lifetime of the quantum system (electrons, atomic nuclei, atoms, etc.). at this level.

Velocity of Sound

— velocity of elastic waves in the environment of low intensity (see. Intensity of the sound) in contrast to the shock waves. In gases and liquids V.of s. $$ v=\sqrt{\frac{K}{\rho}} $$ where $K$ — bulk modulus of elasticity of the medium; $\rho$ — density undisturbed environment. In solids V.of s. Is different for longitudinal and transverse waves.


— one of the main characteristics of the motion of a point. V - vector equal the limit of the ratio of growth $\vec{\Delta \mathrm{r}} $ radius vector $\vec{r}(x, y, z)$ of a point to the time interval $\Delta t$ during which growth was at decreasing unlimited $\Delta t$: $$ \vec{v}=\lim _{\Delta t \rightarrow 0} \frac{\overrightarrow{\Delta r}}{\Delta t}=\frac{\overrightarrow{d r}}{d t} $$ that $ \vec{v}$ - the first derivative of the radius vector in time.

Charles Law

— one of the main gas laws, according to which the pressure of the mass of an ideal gas at constant volume varies linearly with temperature changes: $$p_{t}=p_{0}(1+\beta t)$$ where $p_{t}$ and $p_{0}$ — gas pressure at temperatures $t$ and $0\ ^{\circ} \! {\mathrm{C}}$ respectively, $\beta=1 / 273,15 \mathrm{k}^{-1}$ — temperature coefficient of pressure, established in 1787 France. scientist Jean Charles (1746-1823).

Rotation Frequency

— an amount equal treatment number of revolutions of body rotating at the time of rotation. The unit of R. f. in SI — minus second in the first degree $\left(\mathrm{s}^{-1}\right)$; Common Units R.f. — rpm (rev / min) and revolutions per second (r / c).