The speed of energy propagation = e/n wave is the speed of the wavefront plane wave that travel in the k v wae direction (wavefronts normal to k ). but k is not, in general, the direction in which energy is transported. exb instead, energy propagates along the direction of the poynting vector s s this speed is given by, ray velocity in the sdirection v ray,š 1 where ss exb energy transported by the em wave per unit area and per unit time energy density of the electromagnetic field 2 exb 4.a show that or equivalently, u . -od hint: use b = k x e b (cxa) a (bxc) c(axb) 1 c2-1/() and h v wavek 4.b show that ray, i cosd s where is the angle between k and s

Mga halaman/punong ornamental na di namumulaklak

What structural formula represents 4 electrons shared between two atoms?

1. what is the relationship between wavelength and the penetrating power of an electromagnetic wave? a) the penetrating power has no relationship to the wavelength. b) the penetrating power increases as the wavelength increases. c) the penetrating power decreases as the wavelength increases. d) the penetrating power decreases as the wavelength decreases. 2. as ice melts and turns into water, the speed of sound through the material would most likely do what? justify your answer. a) the speed would not change because the material is always water. b) the speed of sound would increase because the density of water is less than that of ice. c) the speed of sound would increase because energy is added to ice in order to make it melt. d) the speed of sound would decrease because sound travels faster through solids than liquids. 3.which of these waves need a medium to travel through? a) sound b) x-rays c) infrared rays d) visible light