document.write( "Question 823904: I need to make a spear head equal to that of Goliath in the Bible. We know it weighed around 15 lbs and was made of iron. Well, the best we can tell. \r
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document.write( "So I know that 15 lbs of cast iron would equal 240 oz. \r
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document.write( "We know that cast iron weighs 4.166666666666667 oz per cubic inch? (450 lbs per cubic foot = 7,200 oz / 1728 inches per cubic foot = 4.166666666666667)\r
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document.write( "If my math is right, we are looking at 57.6 cubic inches of cast iron would be 15 lbs.\r
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document.write( "So to get an idea of how big I need to make the spear head, lets say it is almost a cone shape 4 inches at the wide end. How long would it need to be?\r
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document.write( "Cone volume = 57.6 cubic inches
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document.write( "Cone base = 4 inches
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document.write( "Cone height = ???\r
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document.write( "I will need to make a prototype. Use that to disperse water to the 57.6 volume. Then make a mold and cast the iron. I know the cone height will actually be short of what I need but at this point I don't have a clue how long it needs to be. At least this should get me into the ball park. From there I will keep working on it until I end up with the 57.6 or a bit more.\r
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document.write( "If you see any error in my math up to this point, please let me know.\r
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document.write( "Kind of a fun project you will have to admit. Thanks a bunch. \n" );
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Algebra.Com's Answer #495997 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! Cone volume = 57.6 cubic inches \n" ); document.write( "Cone base = 4 inches \n" ); document.write( "Cone height = ??? \n" ); document.write( ": \n" ); document.write( "The volume of a cone: V = \n" ); document.write( "Assuming the diameter of the base of the cone = 4 inches, r=2 inches \n" ); document.write( " \n" ); document.write( "multiply both sides by 3 \n" ); document.write( " \n" ); document.write( "divide both sides by \n" ); document.write( "h = \n" ); document.write( "h = 13.75 inches \n" ); document.write( ": \n" ); document.write( "A cone with a volume of 57.6, and a diameter of 4 will be 13.75 inches long \n" ); document.write( " \n" ); document.write( " |