enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Delta potential - Wikipedia

    en.wikipedia.org/wiki/Delta_potential

    Source: [1] The potential splits the space in two parts (x < 0 and x > 0).In each of these parts the potential is zero, and the Schrödinger equation reduces to =; this is a linear differential equation with constant coefficients, whose solutions are linear combinations of e ikx and e −ikx, where the wave number k is related to the energy by =.

  3. Negative energy - Wikipedia

    en.wikipedia.org/wiki/Negative_energy

    The negative-energy particle then crosses the event horizon into the black hole, with the law of conservation of energy requiring that an equal amount of positive energy should escape. In the Penrose process , a body divides in two, with one half gaining negative energy and falling in, while the other half gains an equal amount of positive ...

  4. List of trigonometric identities - Wikipedia

    en.wikipedia.org/wiki/List_of_trigonometric...

    Ptolemy's theorem states that the sum of the products of the lengths of opposite sides is equal to the product of the lengths of the diagonals. When those side-lengths are expressed in terms of the sin and cos values shown in the figure above, this yields the angle sum trigonometric identity for sine: sin(α + β) = sin α cos β + cos α sin β.

  5. Small-angle approximation - Wikipedia

    en.wikipedia.org/wiki/Small-angle_approximation

    Figure 2. A comparison of cos ... (energy) equation of motion ... where the values for sin(0.75) and cos(0.75) are obtained from trigonometric table. The result is ...

  6. Wave equation - Wikipedia

    en.wikipedia.org/wiki/Wave_equation

    For an incident wave traveling from one medium (where the wave speed is c 1) to another medium (where the wave speed is c 2), one part of the wave will transmit into the second medium, while another part reflects back into the other direction and stays in the first medium. The amplitude of the transmitted wave and the reflected wave can be ...

  7. Envelope (waves) - Wikipedia

    en.wikipedia.org/wiki/Envelope_(waves)

    A modulated wave resulting from adding two sine waves of identical amplitude and nearly identical wavelength and frequency. A common situation resulting in an envelope function in both space x and time t is the superposition of two waves of almost the same wavelength and frequency: [2]

  8. List of equations in wave theory - Wikipedia

    en.wikipedia.org/wiki/List_of_equations_in_wave...

    m s −2 [L][T] −2: Spatial position Position of a point in space, not necessarily a point on the wave profile or any line of propagation d, r: m [L] Wave profile displacement Along propagation direction, distance travelled (path length) by one wave from the source point r 0 to any point in space d (for longitudinal or transverse waves) L, d, r

  9. Negative frequency - Wikipedia

    en.wikipedia.org/wiki/Negative_frequency

    A negative frequency causes the sin function (violet) to lead the cos (red) by 1/4 cycle. The ambiguity is resolved when the cosine and sine operators can be observed simultaneously, because cos(ωt + θ) leads sin(ωt + θ) by 1 ⁄ 4 cycle (i.e. π ⁄ 2 radians) when ω > 0, and lags by 1 ⁄ 4 cycle when ω < 0.