document.write( "Question 1141267: The horsepower (hp) that a shaft can safely transmit varies jointly with its speed (in revolutions per minute rpm) and the cube of its diameter. If the shaft of a certain material 2 inches in diameter can transmit 36 hp at 75 rpm, what diameter must the shaft have in order to transmit 73 hp at 45 rpm? \n" ); document.write( "

Algebra.Com's Answer #761781 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Use a constant factor, $\"+k+\"$
\n" ); document.write( "Let $\"+H+\"$ = horsepower
\n" ); document.write( "Let $\"+s+\"$ = speed in rpm
\n" ); document.write( "Let $\"+d+\"$ = diameter in inches
\n" ); document.write( " $\"+H+=+k%2As%2Ad%5E3+\"$
\n" ); document.write( " $\"+36+=+k%2A75%2A2%5E3+\"$
\n" ); document.write( " $\"+36+=+600k+\"$
\n" ); document.write( " $\"+k+=+.06+\"$
\n" ); document.write( "------------------
\n" ); document.write( " $\"+73+=+.06%2A45%2Ad%5E3+\"$
\n" ); document.write( " $\"+73+=+2.7%2Ad%5E3+\"$
\n" ); document.write( " $\"+d%5E3+=+27.037+\"$
\n" ); document.write( " $\"+d+=+3.00136+\"$ in
\n" ); document.write( "-----------------------------
\n" ); document.write( "check the math & get a 2nd opinion if needed\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

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