Model the electromagnetic wave in a microwave oven as a plane traveling wave moving to the left, with an intensity of 23.9 kw/m2. an oven contains two cubical containers of small mass, each full of water. one has an edge length of 6.18 cm, and the other, 11.2 cm. energy falls perpendicularly on one face of each container. the water in the smaller container absorbs 70.0% of the energy that falls on it. the water in the larger container absorbs 91.0%. that is, the fraction 0.300 of the incoming microwave energy passes through a 6.18-cm thickness of water, and the fraction (0.300)(0.300) = 0.090 passes through a 11.2-cm thickness. assume a negligible amount of energy leaves either container by heat. find the temperature change of the water in each container over a time interval of 468 s. (the density and the specific heat of water are 103 kg/m3 and 4 186 j/kg · °c, respectively.)

scattering of light by tiny particles in air to produce the colors we see on sky, is dependent on the following factors:

(i) wavelength of light

(ii) size of the scattering particle  

(iii) distance traveled by light through the atmosphere.

according to rayleigh's law of scattering, the amount of scattering is inversely proportional to the fourth power of its wavelength. shorter the wavelength, greater is its scattering. hence violet/blue light is scattered more than red.

sun's light is a composite light ( visible light) with wavelengths in the range 400 nm (violet) to 700 nm (red). as sunlight passes through our atmosphere, the molecules of air scatter light according to their wavelengths. during sunrise and sunset, the sun's position is below the horizon. hence light from the sun travels a greater distance in the atmosphere when compared to its position a noon.

as sunlight enters the earth's atmosphere, blue light is scattered away and at the end of its journey in the sky, only red and orange wavelengths remain in the beam.

hence at sunrise and sunset, the sky appears reddish orange.