document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=319696>Question 319696</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A siren that has a normal frequency of 1500 hertz is approaching you at 80 mph. What is the pitch that you will hear?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #228959 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=228959\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> You didn't specify a temperature or altitude to determine the speed of sound.<BR>\n" );
document.write( "I'll use 700 mph as the speed of sound.<BR>\n" );
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document.write( "Frequency<BR>\n" );
document.write( "The equation for the observed frequency of sound when the source is traveling toward you is:\r<BR>\n" );
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document.write( "fo = fv/(v &#8722; vt)\r<BR>\n" );
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document.write( "where\r<BR>\n" );
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document.write( "fo is the observed frequency <BR>\n" );
document.write( "f is the emitted frequency <BR>\n" );
document.write( "v is the velocity of sound <BR>\n" );
document.write( "vt is the velocity of the source toward you <BR>\n" );
document.write( "v > vt (vt is less than v)<BR>\n" );
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document.write( "fo = 1500*700/(700 - 80)<BR>\n" );
document.write( "fo =~ 1694 Hz<BR>\n" );
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