document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=499660>Question 499660</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 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 14 hp at 30 rpm? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #337814 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=337814\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 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 14 hp at 30 rpm?<BR>\n" );
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document.write( "hp = k*rpm*d^3<BR>\n" );
document.write( "36 = k*75*8<BR>\n" );
document.write( "k = 36/600 = 0.06<BR>\n" );
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document.write( "14 = 0.06*30*d^3 = 1.8d^3<BR>\n" );
document.write( "d^3 = 14/1.8<BR>\n" );
document.write( "d =~ 1.981 inches\r<BR>\n" );
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