Question

Air pressure may be represented as a function of height above the surface of the Earth as shown below. P(h)=PoE^-.00012h In this function, P0 is air pressure at sea level, and h is measured in meters. Which of the following equations will find the height at which air pressure is 65% of the air pressure at sea level? A. Po=.65PoE^-.00012h B. .65Po=PoE^-.00012h C. .65=h*e^-.00012 D. h=.65e^-.00012

Answer 1

The answer is B because you p(h) = 0.65Po and it shows .65Po=PoE^-0.00012h

Answer 2

The equation to find the air pressure (P(h)) at a height above sea level (h) is given by

$P(h)=P_{0} e^{-0.00012h}$

Where,

• P(h) is the new pressure at height h
• $P_{0}$ is the air pressure at sea level, and
• h is the height (measured in meters).

We want to know the new pressure that is 65% of $P_0$.  So we should substitute $0.65P_0$ in P(h) (new pressure) to get the equation:

$0.65P_0=P_0e^{-0.00012h}$. Answer choice B is the correct one.

ANSWER: B