Inverse Variation

magentarita · #1 $Old$ 11-19-2008, 08:09 PM

The weight of an object varies inversely with square of distance from earth's center (3960 miles). A man weighs 250 lbs on the surface of the earth. How much would he weigh in an airplane flying at 30,000 ft?

Pur · #2 $Old$ 11-19-2008, 10:02 PM

Let W denote the weight of the man. Then from the relationship given in the problem with d denoting the distance from the core of earth gives :

$W \alpha \frac{1}{d^2} \Rightarrow 250 \cdot \frac{1}{\frac{3965.68}{3960}^2}=249.28$

magentarita · #3 $Old$ 11-20-2008, 07:10 AM

Quote:

Originally Posted by Pur $View Post$

Let W denote the weight of the man. Then from the relationship given in the problem with d denoting the distance from the core of earth gives :

$W \alpha \frac{1}{d^2}\Rightarrow 250 \cdot \frac{1}{\frac{3965.68}{3960}^2}=249.28$

What a nice job!