# Atmospheric Pressure?

The rate of change of atmospheric pressure P with respect to altitude h is proportional to P, provided that the temperature is constant. At 15 degrees celsius the pressure is 101.3 kPa at sea level and 87.14 kPa at h=1000. (a) What is the atmospheric pressure at an altitude of 3000m? (b) What is the pressure at the top ot Mount McKinley, at an altitude of 6187?

Relevance

Since they are proportional, we can say that P=h (in terms of there relationship to one another--as one increases, so does the other, and vice versa. This concept is very important to know and allows further understanding of what is meant by "proportional").

Ignore the 15 degress C part, because you don't need it to answer this.

(a)

Set up a ratio.

(Pressure1)/(Altitude1) = (Pressure2)/(Altitude2)

It doesn't matter which pressure/atmosphere you designate as 1 or 2. Just be consistent.

x/3000=87.14/1000

Solve for x; this will give you the atmospheric pressure at 3000m.

(b)

Same as (a), but instead of using 3000, use 6187.