Question

The gravitational attraction betweentwo bodies varies inversely as thesquare of the distance between them.If the force of attraction is 64 poundswhen the distance between the bodiesis 9 feet, what is the distance betweenthem when the force is 36 pounds?

Answer 1

The force for the case 1 is 64 pounds and the distance is 9 feet, it is:

`\begin{gathered} (k)/(9^2)=64 \\ k=5184 \end{gathered}`

Now, if the force is 36 pounds, let solve for the distance:

`\begin{gathered} (k)/(r^2)=36 \\ (5184)/(r^2)=36 \\ r^2=144 \\ r=12 \end{gathered}`

Hence the answer is 12 feet.