document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=465940>Question 465940</A>: <I><SPAN STYLE=\"word-break: break-all;\"> how can i calculate average speed<BR>\n" );
document.write( "when a plane is flying from one city to another and is 550 miles per hour and is 430 miles per hour on the return flight. </SPAN>\n" );
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document.write( "when a plane is flying from one city to another and is 550 miles per hour and is 430 miles per hour on the return flight.<BR>\n" );
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document.write( "Average speed for a round trip is similar to parallel resistors, but times 2.<BR>\n" );
document.write( "Avg speed = 2*550*430/(550 + 430)<BR>\n" );
document.write( "= 473000/980<BR>\n" );
document.write( "=~ 482.65 mph<BR>\n" );
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document.write( "It's always less than the average of the 2 speeds, because more time is spent moving at the lower speed (unless they're the same speed). </SPAN>\n" );
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