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.
The answer is D. Krypton (kr)
Dependent on what you are measuring and what took you are using. Please be more specific.
Answer:
2.7%
Explanation:
Given:
Uncertainty of the speedometer (u)= 2.5km/h
Speed measured at that uncertainty (v) = 92km/h
Percent uncertainty (p) is given as the ratio of the uncertainty to the speed measured then multiplied by 100%. i.e
p =
%
p =
%
p = 2.7%
Therefore, the percent uncertainty is 2.7%