document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=176004>Question 176004</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Flying against the jetstream, a jet travels 2920km in 4 hours. Flying with the jetstream, the same jet travels 7630km in 7 hours. What is the speed of the jet in still air, and what is the speed of the jetstream? <BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #131129 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=131129\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Flying against the jetstream, a jet travels 2920km in 4 hours. Flying with the jetstream, the same jet travels 7630km in 7 hours. What is the speed of the jet in still air, and what is the speed of the jetstream? <BR>\n" );
document.write( "----------------<BR>\n" );
document.write( "2920 km/4 hrs = 730 kph ground speed<BR>\n" );
document.write( "7630 km/7 hrs = 1090 kph ground speed<BR>\n" );
document.write( "The airspeed of the plane is the average, (730+1090)/2<BR>\n" );
document.write( "Airspeed = 910 kph<BR>\n" );
document.write( "The wind speed is the difference between either groundspeed and the airspeed.<BR>\n" );
document.write( "910 - 730 = 180 kph wind speed.<BR>\n" );
document.write( "-------------<BR>\n" );
document.write( "BTW, kilometers and kph are not used in aviation, we use nautical miles and knots.  1 knot is 1 nm/hour.<BR>\n" );
document.write( "Flying with the wind is called downwind, or flying with a tailwind.  Against it is called upwind, or into a headwind.<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );