document.write( "Question 1143219: A paper cup is in the shape of a right circular cone with a diameter of 8cm and a height of 12cm.\r
\n" ); document.write( "\n" ); document.write( "a.) Suppose the cup is filled with water to a depth of 8cm. Calculate the volume of water in the cup. Round to the nearest whole number. (HINT: Use similar triangles.)\r
\n" ); document.write( "\n" ); document.write( "b.) To what depth must the cup be filled in order to be half full of water? Round to the nearest tenth.
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Algebra.Com's Answer #764018 by greenestamps(13200)\"\" \"About 
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\n" ); document.write( "The volume of the cup is

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\n" ); document.write( "a. If the cup is filled to a depth of 8cm, that is 2/3 the full depth, so the radius of the water in the cup will be 2/3 of the full radius, which is 8/3cm. The volume of water is then

\n" ); document.write( "\"V+=+%281%2F3%29%28pi%29%28%288%2F3%29%5E2%29%288%29+=+%28512%2F27%29pi\"

\n" ); document.write( "Since the question asks for an answer as the nearest whole number, perform the calculation and round as required.

\n" ); document.write( "Note that, though the problem gives a hint about using similar triangles, there is a much faster way to answer this question. If the height of the water in the cup is 2/3 the full height of the cup, then the volume of water in the cup is (2/3)^3 of the total volume:

\n" ); document.write( "\"%28%282%2F3%29%5E3%29%2864pi%29+=+%28512%2F27%29pi\"

\n" ); document.write( "b. This question is answered far more easily using the concept noted above.

\n" ); document.write( "If the volume is 1/2 of the total volume, then the height of the cone (depth of the water) is the full height, multiplied by the CUBE ROOT of 1/2.

\n" ); document.write( "\"h+=+12%2A%281%2F2%29%5E%281%2F3%29+=+9.5244\" to 4 decimal places.

\n" ); document.write( "Than round as directed.
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