Two identical speakers are set some distance apart in a large open field. Both are producing sound, in unison, with a wavelength of 4 m. An observer wandering around the field notices that the sound is surprisingly loud at certain locations and unusually quiet at others. The observer concludes that this is the effect of interference between the two sources of sound waves. For each location, indicate which sort of interference would occur at that point. 1. Constructive interference
2. Destructive interference
3. In between interference

a. 16 m from one speaker and 24 m from the other
b. 13 m from one speaker and 19 m from the other
c. 11 m from one speaker and 7 m from the other
d. 12 m from one speaker and 14 m from the other
e. 16 m from one speaker and 13 m from the other
f. 20 m from each speaker
g. 19 m from one speaker and 14 m from the other

gravity

explanation:

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.