Solve the variation problem.
-The gravitational attraction between two masses varies inversely as the square of the distance between them. If the force of attraction is 2.25 lb when the masses are 4 ft apart, what is the attraction when the masses are 6 ft apart?
A)3 pounds
B)1 pound
C)2 pounds
D)4 pounds

Question

Quizplus · Accepted Answer

The gravitational force between two masses is given by $F = \frac{k}{r^2}$, where $F$ is the force of attraction, $k$ is a constant, and $r$ is the distance between the masses. Given $F = 2.25$ lbs when $r = 4$ ft, we can find $k = 2.25 \times 4^2 = 36$. When $r = 6$ ft, $F = \frac{36}{6^2} = \frac{36}{36} = 1$ pound.

Solve the Variation Problem