document.write( "Question 576243: A song on a 45 rpm record was 270 seconds long. How many degrees did the record rotate during the song? \n" ); document.write( "
Algebra.Com's Answer #369777 by Edwin McCravy(20063)\"\" \"About 
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document.write( "Each rotation is 360° so 45rpm = 45×360° rotations/minute\r\n" );
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document.write( "We convert 45 revolutions/minute to degrees/second\r\n" );
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document.write( "We begin with this fraction:\r\n" );
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document.write( "\"45rev%2F%28min%29\"\r\n" );
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document.write( "Each revolution is 360 degrees, so we multiply by this unit fraction \"360deg%2F%281rev%29\".  So we have:\r\n" );
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document.write( "\"45rev%2Fmin\"×\"360deg%2F%281rev%29\"  \r\n" );
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document.write( "Each minute is 60 seconds so we multiply by the unit fraction \"1min%2F%2860sec%29\"\r\n" );
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document.write( "\"45rev%2Fmin\"×\"%28360deg%29%2F%281rev%29\"×\"%281min%29%2F%2860sec%29\"\r\n" );
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document.write( "We cancel the rev's and the min's\r\n" );
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document.write( "\"45cross%28rev%29%2Fcross%28min%29\"×\"360deg%2F%281cross%28rev%29%29\"×\"1cross%28min%29%2F%2860sec%29\"\r\n" );
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document.write( "\"expr%2845%2A360%2F60%29\"\"deg%2F%28sec%29\"\r\n" );
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document.write( "That comes out to \r\n" );
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document.write( "270 degrees per second.\r\n" );
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document.write( "So 270 seconds at 270 degrees per second is a rotation through 270×270\r\n" );
document.write( "or 72900 degrees.\r\n" );
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document.write( "Edwin
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