Math Help - exponential functions

1. exponential functions

If the temp is constant, then the atmospheric pressure P varies with the altitude above sea level h

P = p0 e ^ -kh

where p0 is the atmospheric pressure at sea level and k is a constant. If the atmospheric pressure is 100kPa at sea level and 85kPa at 1200m, find the atmospheric pressure at an altitude of 3600m. How fast is the atmospheric pressure changing with respect to altitude at an altitude of 3600m.

Help start me off?? Any help would be great!

2. Originally Posted by youmuggles
If the temp is constant, then the atmospheric pressure P varies with the altitude above sea level h

P = p0 e ^ -kh

where p0 is the atmospheric pressure at sea level and k is a constant. If the atmospheric pressure is 100kPa at sea level and 85kPa at 1200m, find the atmospheric pressure at an altitude of 3600m. How fast is the atmospheric pressure changing with respect to altitude at an altitude of 3600m.

Help start me off?? Any help would be great!
Hi youmuggles,

Ok, here's a start....

$P=P_0e^{-kh}$

$85=100e^{-1200k}$

Solve for k.

Use that constant to find find the pressure at 3600 meters.

$P=100e^{-k(3600)}$