Which lists the waves in order of frequency, from highest to lowest.

x-rays, gamma rays, ultraviolet
radio waves, visible light, x-rays
ultraviolet, microwaves, gamma rays
visible light, infrared, microwaves

The correct order of waves in the descending order of frequency is - Visible light,infrared ,micro wave.

EXPLANATION:

As per electromagnetic spectrum, the gamma wave has the maximum frequency and radio wave has the least frequency.

If we arrange all the electromagnetic waves in the descending order of frequency, then they are arranged as follows-

Gamma rays > X- ray > U.V ray > Visible light >  Infrared wave  > Micro wave >  Radio wave.

As per the question, we have four options.

The correct order of waves in descending order of frequency is D). Visible light, infrared wave, micro wave.

the part of the wave he is travelling on is the crest

v=ir = 3x15 =45 v