document.write( "Question 475300: A dozen golf balls fit inside the shape of a rectangular prism. The golf balls are packed tightly together and they touch top, bottom and side of the box. What percentage of the volume within the box is air?\r
\n" );
document.write( "\n" );
document.write( "I have the answer but have no idea how they arrived at it.
\n" );
document.write( "Air would accupy 47.6 percent of the volume of the box. (100-52.4=47.6)\r
\n" );
document.write( "\n" );
document.write( "How can you get this answer when the question give no numbers? \n" );
document.write( "
Algebra.Com's Answer #325909 by ccs2011(207)![]() ![]() You can put this solution on YOUR website! Even though they don't give any numbers, they do give reference points: \n" ); document.write( "Shape is rectangular prism: Volume = length*width*depth \n" ); document.write( "Golf balls are like spheres: Volume = \n" ); document.write( "Remember the goal isn't to determine the actual volume just comparing the volume the golf balls take up with the volume of the entire box. \n" ); document.write( "Percentage is just a ratio. \n" ); document.write( "Now every golf ball is identical in size, so the radius is constant. \n" ); document.write( "Since we do not know the radius our volumes will be in terms of r. \n" ); document.write( "The volume of 12 golf balls = \n" ); document.write( "Now the tricky part is getting the volume of the box in terms of r. \n" ); document.write( "Now the dimensions of this box can be anything as long as it holds 12 golf balls perfectly. The easiest thing to do is imagine a long sleeve where all 12 balls are stacked on top of each other. Then it is 12 golf balls high, and length and width is same as length of 1 golf ball. Now remember that length of a circle is the diameter which is twice the radius. \n" ); document.write( "Now we know the dimensions: \n" ); document.write( "length = width = 2r \n" ); document.write( "depth = 12*2r = 24r \n" ); document.write( "Volume = \n" ); document.write( "Now the ratio of golf balls volume to box volume is: \n" ); document.write( " \n" ); document.write( "So 52.4% of the box is taken up by the golf balls. \n" ); document.write( "Leaving 47.6% of the box to be taken up by air. \n" ); document.write( "Hope that helped :) \n" ); document.write( " |