--%>

calculate the intensity I along y axis

As shown in the figure below, a source at S is sending out a spherical wave:

E1=(A×D/r) cos(wt-2πr/λ); where r is the distance to source S. In addition, there is another plane wave propagating along x axis: E2=Acos(wt-2πx/λ). 

These two waves both projected on a vertical screen as shown in the figure. Please calculate the intensity I along y axis (I should be a function of y, the distance from x axis). D is the distance between the screen and the source.

 

381_optics.png

Hint: For a wave E=E0cos (wt + q), I = 2 = E02. Also r = (D2 + y2)1/2.

For k<<1,  (1+k2)1/2» 1+k2/2.   cosA+cosB = 2cos[(A+B)/2] cos[(A-B)/2]

   Related Questions in Physics

  • Q : What is Universal age paradox Universal

    Universal age paradox: The two most straightforward techniques of computing the age of the Universe -- via red-shift measurements, and via stellar evolution -- outcome incompatible outcomes. Recent (in mid 1990s) measurements of the distances of far-a

  • Q : What is Lumeniferous aether

    Lumeniferous aether: The substance that filled all the vacant spaces between matter that was employed to elucidate what medium light was "waving" in. Now it has been harmed the reputation of, as Maxwell's equations entail that electromagnetic radiatio

  • Q : Define Relativity principle Relativity

    Relativity principle: The principle, utilized by Einstein's relativity theories, that the laws of physics are similar, at least qualitatively, in all frames. That is, there is no frame which is better (or qualitatively any different) from any other. T

  • Q : Define Van der Waals force Van der

    Van der Waals force (J.D. van der Waals): The forces responsible for non-ideal behavior of gases, and for lattice energy of molecular crystals. There are three main causes: dipole-dipole interaction; dipole-induced dipole moments; and dispersion a for

  • Q : What is Coriolis pseudoforce Coriolis

    Coriolis pseudoforce (G. de Coriolis; 1835): The pseudoforce that arises since of motion relative to a frame that is itself rotating relative to the second, inertial frame. The magnitude of the Coriolis "force" is tot

  • Q : Define Occams razor or Ockhams razor

    Occam's [or Ockham's] razor (William of Occam [or Ockham]; c. 1340): It is the suggestion that the simpler a theory is the better. When two theories forecast the phenomena to the similar accuracy, then the one that is simpler is the better one. Furthe

  • Q : Define Luxon Luxon : The particle that

    Luxon: The particle that travels solely at c (that is the speed of light in vacuum). All luxons have a rest mass of exactly zero. Though they are mass less, luxons do take momentum. The photons are the prime illustration of luxons (that is the name it

  • Q : Formula for acceleration What is the

    What is the appropriate formula employed to compute the acceleration? Explain in brief.

  • Q : Explain Boyle's law Boyle's law (R.

    Boyle's law (R. Boyle; 1662); Mariotte's law (E. Mariotte; 1676) - The product result of the volume and pressure of an ideal gas at constant (steady) temperature is constant.

  • Q : Becquerel Becquerel : Bq (after A.H.

    Becquerel: Bq (after A.H. Becquerel, 1852-1908) - The derived SI unit of the activity stated as the activity of radionuclide decay at a rate, on the average, of one nuclear transition every 1 s; it hence has units of s-1.