document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=152698>Question 152698</A>: <I><SPAN STYLE=\"word-break: break-all;\"> In studying the frictional effects on a flywheel, the revolutions per minute R that it makes as a function of the time t (in min) is given by R = 4520(0.750)^2.50t.  Find t for R = 1950 r/min </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #113018 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=113018\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> In studying the frictional effects on a flywheel, the revolutions per minute R that it makes as a function of the time t (in min) is given by R = 4520(0.750)^2.50t. Find t for R = 1950 r/min<BR>\n" );
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document.write( "R = 4520(0.750)^2.50t<BR>\n" );
document.write( "1950 r/min = 4520(3/4)^(2.5t)<BR>\n" );
document.write( "0.431416 = (3/4)^(2.5t)<BR>\n" );
document.write( "Take the log of both sides to get:<BR>\n" );
document.write( "(2.5t) = log(0.431416)/log(3/4)<BR>\n" );
document.write( "2.5t = -0.365104<BR>\n" );
document.write( "t = -0.146042<BR>\n" );
document.write( "Comment: This answer doesn't make any sense.<BR>\n" );
document.write( "The time should not be negative.<BR>\n" );
document.write( "==================================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );