SOLUTION: Hopefully - this is my last question! I'm a little confused on this one, probably because it is a word problem. The equation P(a) = 14.7e^-0.21a, where a is the altitude above sea

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: Hopefully - this is my last question! I'm a little confused on this one, probably because it is a word problem. The equation P(a) = 14.7e^-0.21a, where a is the altitude above sea      Log On


   



Question 83648: Hopefully - this is my last question! I'm a little confused on this one, probably because it is a word problem.
The equation P(a) = 14.7e^-0.21a, where a is the altitude above sea level measured in miles yields the atmospheric pressure in pounds per square inch. if the atmospheric pressure is apporximately 11.35 pounds per square inch, find that altitude avoe sea level. Express to the nearest hundred feet.

Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
the 11.35 is the P (which is a function of (a)), so you need to find the value of a in the equation

11.35=14.7e^(-0.21a) ... taking natural log gives, ln(11.35)=ln(14.7)-0.21a

ln(11.35)-ln(14.7)=(-0.21)a ... (ln(11.35)-ln(14.7))/(-0.21)=a ... a approximately equals 1.232 mi.