document.write( "Question 462613: A large grain silo consists of a cylinder measuring 30 feet tall, a diameter at the base of 18 feet, and a hemisphere (half-dome) on top. How many gallons of paint will be required to paint this silo if a gallon of the paint to be used covers 500 square feet? \n" ); document.write( "
Algebra.Com's Answer #319492 by lwsshak3(11628)\"\" \"About 
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A large grain silo consists of a cylinder measuring 30 feet tall, a diameter at the base of 18 feet, and a hemisphere (half-dome) on top. How many gallons of paint will be required to paint this silo if a gallon of the paint to be used covers 500 square feet.
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\n" ); document.write( "formulas used:
\n" ); document.write( "Surface area of sphere=4πr^2
\n" ); document.write( "Circumference = 2πr
\n" ); document.write( "r=diameter/2=18/2=9 ft
\n" ); document.write( "height, h=30 ft
\n" ); document.write( "..
\n" ); document.write( "Surface area of half-dome=1/2*4*π*r^2=2π*81=162π
\n" ); document.write( "Surface area of bottom=π*r^2=81π
\n" ); document.write( "Surface area of cylinder=circumference*height=2πr*30=540π
\n" ); document.write( "Total surface area of silo=(162+81+540)π=783π sq ft
\n" ); document.write( "ans:
\n" ); document.write( "Paint required=783π/500=4.92gal \n" ); document.write( "
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