What will happen to the pitch of a sound as that sound’s source approaches an observer? explain why this happens, based on what you have learned about wave properties. use 3 content related sentences

The pitch of a sound is decreased, when a sound source approaches the observer.

Explanation:

Pitch is nothing but it is a property that helps to determine whether the sound is high or low. Doppler effect helps to understand this concept easily. The pitch of the sound is mainly calculated based on the frequency of the sound wave arose from the sound source.

As the wellspring of sound waves moves toward an audience, the sound waves draw nearer together, expanding their recurrence and the pitch of the sound.

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.