document.write( "Question 967595: Two cylinders are such that the ratio of their base radii is 2 : 1 and the ratio of their heights is 3 : 1. Find the ratio of their respective volumes. \n" ); document.write( "
Algebra.Com's Answer #591427 by Theo(13342)![]() ![]() You can put this solution on YOUR website! ratio of heights is 3 to 1. \n" ); document.write( "ratio of radii of the base is 2 to 1.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "ratio of volume is?\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "volume = pi * r^2 * h\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "let the radius of the smaller cylinder be r. \n" ); document.write( "then the radius of the larger cylinder is 2r.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "let the height of the smaller cylinder be h. \n" ); document.write( "then the height of the larger cylinder is 3h.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the volume of the smaller cylinder is pi * r^2 * h.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the volume of the larger cylindere is pi * (2r)^2 * (3h).\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "let v1 = volume of smaller cylinder.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "let v2 = volume of larger cylinder.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the ratio of the volume of the smaller cylinder to the volume of the larger cylinder is:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "v1 / v2 = (pi * r^2 * h) / (pi * (2 * r)^2 * (3 * h)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "simplify to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "v1 / v2 = (pi * r^2 * h) / (pi * 4 * r^2 * 3 * h)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the pi and the r^2 and the h in the numerator and denominator cancel out and you are left with:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "v1 / v2 = 1 / (4 * 3) which simplfies to:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "v1 / v2 = 1 / 12.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "that'a the ratio of the volumes.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "as an example:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "let the radius of the smaller cylinder be 5 and the height of the smaller cylinder be 10.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the radius of the larger cylinder is 10 and the height of the larger cylinder is 30.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "v1 = pi * 5^2 * 10 = 250 * pi.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "v2 = pi * 10^2 * 30 = 3000 * pi.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "v1 / v2 = 250 / 3000 - 25 / 300 = 1 / 12.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |