document.write( "Question 26024: To measure the speed of the jet stream, a weather plane left its base at noon and flew 800km directly against the stream with an air speed of 750 km/h. It then returned directly to its base, arriving at 2:24 P.M. What was the speed of the jet stream?
\n" ); document.write( "Thank you. \n" ); document.write( "
Algebra.Com's Answer #13979 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
Dividing 800km by 750km you get 1.066666 hrs. or 64 min.
\n" ); document.write( "The roundtrip, according to your posting, is 144 min.
\n" ); document.write( "So,the return trip took 80 min.
\n" ); document.write( "That would mean the return trip was against the wind.
\n" ); document.write( "Using d=rt you have this kind of data:
\n" ); document.write( "Flight out Data:
\n" ); document.write( " distance=800km; time=64min; rate=750km/hr
\n" ); document.write( "Flight back Data:
\n" ); document.write( " distance=800km; time=80min; rate=800km/80min=10km/min=600km/hr
\n" ); document.write( "Let plane speed be \"p\" and wind speed be \"w\"
\n" ); document.write( "Down wind you have: p+w=750km/hr
\n" ); document.write( "Against wind you have: p-w=600km/hr
\n" ); document.write( "Solve that system for P and w:
\n" ); document.write( "Adding the equations you get 2p=1350
\n" ); document.write( " p=675km/hr
\n" ); document.write( "Substituting you get p+w=750
\n" ); document.write( " 675+w=750
\n" ); document.write( " w=75
\n" ); document.write( "The wind speed is 75km/hr\r
\n" ); document.write( "\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H. \n" ); document.write( "
\n" );