SOLUTION: A jet liner takes 1.2 times as long to flied from Paris to New York (the distance from Paris to New York is 3600 miles) as to return if the jet cruises at 550 miles per hour in sti

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Question 1086555: A jet liner takes 1.2 times as long to flied from Paris to New York (the distance from Paris to New York is 3600 miles) as to return if the jet cruises at 550 miles per hour in still air. What is the average rate of the wind drawing in the direction of Paris from New York?
p.s. the direction of the wind to be solved is FROM New York to Paris, which means the number is negative, or there should be a negative number. My Professor said a FORCE going to an opposite direction is negative.
p.p.s. The travels stated in the problem is Paris to New york :). Hope that could hep sir/maam. Thank you!

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +-w+ = the windspeed the plane sees
when it travels from Paris to NY
+550+-+w+ mi/hr is the plane's speed
when it travels from Paris to NY
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The wind is in the opposite direction on the return trip, so
+550+%2B+w+ mi/hr is the plane's speed
when it travels from NY to Paris
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Let +t+ = time in hrs for the plane to travel
from NY to Paris
+1.2t+ = time in hrs for the plane to travel
from Paris to NY
----------------------------------------
Equation for Paris to NY:
(1) +3600+=+%28+550+-+w+%29%2A1.2t+
Equation for NY to Paris:
(2) +3600+=+%28+550+%2B+w+%29%2At+
---------------------------------
(2) +t+=+3600+%2F+%28+550+%2B+w+%29+
and
(1) +3600+=+%28+550+-+w+%29%2A1.2%2A%28+3600+%2F+%28+550+%2B+w+%29+%29+
(1) ++550+%2B+w+++=+1.2%2A%28+550+-+w+%29+
(1) +550+%2B+w+=+660+-+1.2w+
(1) +2.2w+=+110+
(1) +w+=+50+
The wind speed the plane sees when flying from
Paris to NY is -50 mi/hr ( headwind, not a tailwind )
-------------------------------
check:
(2) +3600+=+%28+550+%2B+w+%29%2At+
(2) +3600+=+%28+550+%2B+50+%29%2At+
(2) +3600+=+600t+
(2) +t+=+6+ hrs
and
(1) +3600+=+%28+550+-+w+%29%2A1.2t+
(1) +3600+=+%28+550+-+50+%29%2A1.2t+
(1) +3600+=+500%2A1.2t+
(1) +3600+=+600t+
(1) +t+=+6+ hrs
OK