document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=215485>Question 215485</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/0536302804/algebrahomeworkh>College Mathematics II</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> The loudness level of sound can be expressed by comparing the sound's intensity to the intensity of a sound barely audible tot he human ear.  The formula D = 10(log I - log I<sub>0) describes the loudness level of a sound.  D, in decibels, where I is the intensity of the sound, in watts per meter^2, and I<sub>0 is the intensity of a sound barely audible to the human ear.\r<BR>\n" );
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document.write( "(a.)  Express the formula so that the expression in patentheses is written as a single logarithm.\r<BR>\n" );
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document.write( "(b.)  Use the form of the formula from part (a) to answer this question:  If a sound has an intensity 100 times the intensity of a softer sound, how much larger on the decibel scale is the loudness level of the more intense sound? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #162835 by </B><A HREF=/tutors/aboutme.mpl?userid=Earlsdon><B>Earlsdon(6294)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Earlsdon><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=162835\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> (a) Express:<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=D+=+10%28Log%28I%29-Log%28I%5B0%5D%29%29 ALIGN=MIDDLE  ALT=\"D+=+10%28Log%28I%29-Log%28I%5B0%5D%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > as a single logarithm: Applying the quotient rule for logarithms, we get:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28D+=+10%28Log%28I%2FI%5B0%5D%29%29%29 ALIGN=MIDDLE  ALT=\"highlight%28D+=+10%28Log%28I%2FI%5B0%5D%29%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > For part (b), substitute <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=I+=+100 ALIGN=MIDDLE  ALT=\"I+=+100\"   DISABLED_style= \"max-width:90%; height:auto;\" > and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=I%5B0%5D+=+1 ALIGN=MIDDLE  ALT=\"I%5B0%5D+=+1\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(b) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=D+=+10%28Log%28100%2F1%29%29 ALIGN=MIDDLE  ALT=\"D+=+10%28Log%28100%2F1%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=D+=+10%28Log%28100%29%29 ALIGN=MIDDLE  ALT=\"D+=+10%28Log%28100%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=D+=+10%282%29 ALIGN=MIDDLE  ALT=\"D+=+10%282%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28D+=+20%29 ALIGN=MIDDLE  ALT=\"highlight%28D+=+20%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
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