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Unformatted text preview: Biot number are, from Table 41, 4698 . 1 and 9081 . 1 1 1 = = A Once the constant is determined from Table 42 corresponding to the constant J 1 =1.9081, the Fourier number is determined to be 10 cm Wood log, 10 C Hot gases 700 C 251 . ) 2771 . ( ) 4698 . 1 ( 500 10 500 420 ) / ( ) , ( 2 2 1 ) 9081 . 1 ( 1 1 = = = e r r J e A T T T t r T o o i o which is above the value of 0.2. Therefore, the oneterm approximate solution (or the transient temperature charts) can be used. Then the length of time before the log ignites is min 81.7 = = = = s 4904 /s) m 10 28 . 1 ( m) 05 . )( 251 . ( 2 7 2 2 o r t 428...
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This note was uploaded on 01/19/2012 for the course PHY 4803 taught by Professor Dr.danielarenas during the Fall '10 term at UNF.
 Fall '10
 Dr.DanielArenas
 Thermodynamics, Mass, Heat

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