Answer: 
At sea level, there is one standard atmospheric pressure which is equal to 101.325 kilopascals.
The pressure of faintest sound that a human ear can hear is 20 micro-pascals.
taking the ratio of two:
Hence, the atmospheric pressure at sea level is times greater than the faintest sound that a human ear can hear.
Answer:
10 hours
Explanation:
If the plane flies at 500 miles per hour, it flies 500 miles every hour. So, to find out how many hours it will take to fly 5000, you simply do 5000/500.
I think the correct answer would be one half the wavelength. Waves would "feel bottom" when the water is at the depth of 0.5 of the wavelength. "Feel bottom" is a term used to describe that the depth of water affects the wave properties. Hope this answers the question.
