Question

Despite their extensive applications in communication systems, radio waves a not the only form of EM waves present in our atmosphere. Another form of EM radiation plays an even more important role in our life (and the life of our planet): sunlight. The sun emits over a wide range of frequencies; however, the fraction of its radiation that reaches earth's surface is mostly in the visible spectrum. (Note that about 35% of the radiation coming from the sun is absorbed directly by the atmosphere before even reaching the earth's surface.) The earth, then, absorbs this radiation and reemits it as infrared waves.
Based on this information, which of the following statements is correct? Check all that apply.

a. The earth absorbs visible light and emits radiation with a shorter wavelength.
b. The earth absorbs visible light and emits radiation with a longer wavelength.
c. The earth absorbs visible light and emits radiation with a lower frequency.
d. The earth absorbs visible light and emits radiation with a higher frequency.

Answer 1

Let us assume that the definition of frequency, wavelength and wave speed is determined by the function

$f = \frac{v}{\lambda}$

Here,

v = Velocity of wave

$\lambda$ = Wavelength

f = Frequency

We know that the earth has the ability to absorb visible light but that it can also emit a longer radiation wavelength. This assessment allows us to confirm that option A. Is correct. In turn, if said wavelength is large, being inversely proportional to the frequency,

$\lambda \propto \frac{1}{f}$

This does tend to be lower radiation. The correct options are:

A.The earth absorbs visible light and emits radiation with a longer wavelength.

B.The earth absorbs visible light and emits radiation with a lower frequency.