If the temperature is constant then the atmospheric pressure P (in pounds/square inch) varies with the altitude above sea level h in accordance with the law
P=Poe^-kh
where Po is the atmospheric pressure at sea level and k is a constant. If the atmospheric pressure is 15 lb/in^2 at sea level and 12.5lb/in^2 at 4000 ft, find the atmospheric pressure at an altitude of 12,000 ft.
How fast is the atmospheric pressure changing with respect to altitude at an altitude of 1200ft?