document.write( "Question 822055: You are to design a fountain for the garden of one of Emily’s customers.
\n" ); document.write( "• The fountain will have a cylindrical base with a cone on top.
\n" ); document.write( "• The cylindrical base will have a diameter of 1 m.
\n" ); document.write( "• The fountain is to be made of concrete.
\n" ); document.write( "• The entire fountain is to be coated with protective paint.
\n" ); document.write( "a) Make a sketch of your design, showing all
\n" ); document.write( "dimensions.
\n" ); document.write( "b) How much concrete is needed to make the
\n" ); document.write( "fountain?
\n" ); document.write( "c) What is the surface area that needs to be
\n" ); document.write( "painted?
\n" ); document.write( "d) Concrete costs $100/m3. Each litre of
\n" ); document.write( "protective paint costs $17.50 and covers
\n" ); document.write( "5 m2. Find the total cost of the materials
\n" ); document.write( "needed to make the fountain.
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Algebra.Com's Answer #494605 by KMST(5328)\"\" \"About 
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Not enough data, and not reasonable data.
\n" ); document.write( "You must be missing some details of the problem.
\n" ); document.write( "A 1 meter wide cylindrical base means a monstrously large fountain. It would be appropriate for a city square, but not for the garden of any citizen.
\n" ); document.write( "A 1 meter diameter would be appropriate for the top cone of the fountain in someone's garden,
\n" ); document.write( "but even assuming 1 meter diameter and 1 meter base height, there are other design issues that are not specified.
\n" ); document.write( "Is the top cone part a solid cone?
\n" ); document.write( "If there is a cavity in the cone, is the wall of the cone uniformly thick? How thick?
\n" ); document.write( "How wide is the base?
\n" ); document.write( "Is the base a hollow stem? Or is it a solid cylinder made of concrete?
\n" ); document.write( "If it is hollow, how thick is the wall of the base cylinder?
\n" ); document.write( "Depending on design, it could be a complicated problem.
\n" ); document.write( "There is also the issue of how realistic you have to be.
\n" ); document.write( "Do you need to buy a whole number of liters of paint, or can you buy exactly the amount you need, even if it is a crazy decimal number, such as 0.17 liter?
\n" ); document.write( "What about the cement? Can you order 0.43 m^3?
\n" ); document.write( "
\n" ); document.write( "The simplest, if ugly, design would be a cylinder with a conical hollow at the top.
\n" ); document.write( "In cross section, it would look like this:
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\n" ); document.write( "VOLUME:
\n" ); document.write( "The volume of that is the volume of the cylinder minus the volume of the cone.
\n" ); document.write( "If the cylinder and cone were 1 m in diameter (0.5m radius), with a cylinder height of 1m, and a cone height (depth) of 0.25m, the volume, in m^3 would be
\n" ); document.write( "\"pi%2A0.5%5E2%2A1-pi%2A0.5%5E2%2A1%2F3=0.25pi-0.25pi%2F3=0.5236\"
\n" ); document.write( "At $100/m^3, the cement to make that would cost $52.36.
\n" ); document.write( "
\n" ); document.write( "SURFACE AREAS:
\n" ); document.write( "The surface to be painted would be the lateral surface of the cylinder,
\n" ); document.write( "calculates as \"perimeter%2Aheight=pi%2Adiameter%2Aheight\" ,
\n" ); document.write( "plus the lateral surface of the cone,
\n" ); document.write( "calculated as \"perimeter%2Aheight%2F2=pi%2Adiameter%2Aheight\"
\n" ); document.write( "For the measurements assumed above, the area in m^2 would be
\n" ); document.write( "\"pi%2A1%2A1%2Bpi%2A1%2A0.25%2F2=pi%2Bpi%2F3=4pi%2F3=4.19\"
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\n" ); document.write( "COST:
\n" ); document.write( "The cost for 1 liter of paint and 0.53m^3 of concrete would be
\n" ); document.write( "$17.50 + $53.00 = $70.50
\n" ); document.write( "
\n" ); document.write( "The fountain I would design, in cross-section, would look like this:
\n" ); document.write( " The height of the cone is half the diameter.
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\n" ); document.write( "VOLUMES:
\n" ); document.write( "The volume of cement in the cone is the volume of a cone with a 0.5m radius and a 0.25m height, minus the volume of a cone with a 0.45m radius and a 0.225m height. In \"m%5E3\" , it is
\n" ); document.write( "
\n" ); document.write( "The volume of cement in the base is the volume of a cylinder with a 0.1m radius and a 1m height, minus the volume of a cone with a 0.08m radius and a 1m height. In \"m%5E3\" , it is
\n" ); document.write( "\"pi%2A0.1%5E2%2A1-pi%2A0.08%5E2%2A1=pi%28.01-.0064%29=0.036pi=0.01131\"
\n" ); document.write( "The total volume of concrete is
\n" ); document.write( "\"0.01774m%5E3%2B0.01131m%5E3=0.02905m%5E3\" .
\n" ); document.write( "At $100/m^3 that would cost $2.91.
\n" ); document.write( "
\n" ); document.write( "SURFACE AREAS:
\n" ); document.write( "The outside cone has a radius of 0.5m and a height of 0.25m.
\n" ); document.write( "Its slant height, in m, is
\n" ); document.write( "\"sqrt%280.5%5E2%2B0.25%5E2%29=sqrt%280.25%2B0.0625%29=sqrt%280.3125%29=0.559\"
\n" ); document.write( "The perimeter of the base, in m, is \"pi\" , because the diameter is 1m.
\n" ); document.write( "The outside surface area of the cone, in \"m%5E2\" , is
\n" ); document.write( "\"pi%2A0.559%2F2=0.878\".
\n" ); document.write( "The surface area of the cone insides plus the rim is about the same.
\n" ); document.write( "The outside surface area of the cylindrical base, in \"m%5E2\" , is
\n" ); document.write( "\"pi%2A0.2%2A1=0.628\"
\n" ); document.write( "The total area to be painted, in \"m%5E2\" , is about
\n" ); document.write( "\"0.878%2B0.878%2B0.628=2.38\"
\n" ); document.write( "That would require less than 1 liter of paint.
\n" ); document.write( "
\n" ); document.write( "COST:
\n" ); document.write( "Buying 1 liter of paint, plus 0.03m^3 concrete would cost
\n" ); document.write( "$17.50 + $3.00 = $20.50
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