document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1131513>Question 1131513</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Two airplanes leave from an airport at the same time. One travels due south at a speed of <BR>\n" );
document.write( "420<BR>\n" );
document.write( " miles per hour, and the other travels due west at a speed of <BR>\n" );
document.write( "560<BR>\n" );
document.write( " miles per hour. How long until the distance between the two airplanes is <BR>\n" );
document.write( "3150<BR>\n" );
document.write( " miles? </SPAN>\n" );
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document.write( "Due south and due west are paths that are perpendicular to each other, so a triangle showing the planes' paths and the distance between the planes is a right angle.<br><BR>\n" );
document.write( "Observe that the two speeds are 420 = 140*3 mph and 560 = 140*4 mph.  So the right triangle is a scale model of the 3-4-5 right triangle; the distance between the planes is increasing at a rate of 140*5 = 700 mph.<br><BR>\n" );
document.write( "The number of hours required for the distance between the planes to be 3150 miles is<br><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3150%2F700+=+4.5 ALIGN=MIDDLE  ALT=\"3150%2F700+=+4.5\"   DISABLED_style= \"max-width:90%; height:auto;\" ><br><BR>\n" );
document.write( "ANSWER: It will take 4.5 hours for the distance between the planes to be 3150 miles. </SPAN>\n" );
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