document.write( "Question 1006226: The gravitational force between two bodies varies inversely as the square of the distance between them. If the force between two bodies is 18 N when the distance between them is 10 km, find the force between the bodies when the distance between them is 7.5 km. \n" ); document.write( "
Algebra.Com's Answer #622373 by Theo(13342)\"\" \"About 
You can put this solution on YOUR website!
y = k/x^2\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "y is the gravitaional force.
\n" ); document.write( "x is the distance between them.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "y = 18
\n" ); document.write( "x = 10\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "y = k/x^2 becomes 18 = k/10^2 which becomes 18 = k/100.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "solve for k to get k = 1800\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "now that you know k, you can solve the problem.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "when the distance between them is 7.5 km, the equation becomes:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "y = 1800/(7.5)^2 which becomes y = 1800/56.25 \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "solve for y to get y = 32.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "
\n" );