The Earth itself is a source of terrestrial radiation. Radioactive materials including uranium, thorium, and radium exist naturally in soil and rock. Essentially all air contains radon<span> , which is responsible for most of the dose that Americans receive each year from natural background sources.</span>
I believe it is A, if I am remembering correctly from my last semester class.
Who knows, not me, not me and not me again
I have no idea what you are trying to ask sorry
The answer is 0.5 km because 5 km/s divided by 10 Hz is 0.5. This makes your wavelength 0.5 km.