SOLUTION: a plane flies 400 miles downwind in the same amount of time as it takes to travel 320 miles upwind. of the plane can fly at 360 mph in still air, find the velocity of the wind.

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Question 405646: a plane flies 400 miles downwind in the same amount of time as it takes to travel 320 miles upwind. of the plane can fly at 360 mph in still air, find the velocity of the wind.
Answer by checkley79(3341) About Me  (Show Source):
You can put this solution on YOUR website!
D=RT
400=(360+W)T
T=400/(360+W) FOR THE DOWNWIND FLIGHT.
320=(360-W)T
T=320/(360-W) FOR THE UPWIND FLIGHT.
BECAUSE THE TIMES (T) ARE EQUAL THEN:
400/(360+W)=320/(360-W) CROSS MULTIPLY.
400(360-W)=320(360+T)
144,000-400W=115,200+320T
-400W-320W=115,200-122,000
-720W=-28,800
W=-28,800/-720
W=40 MPH. IS THE WIND SPEED.
PROOF:
400/(360+40)=320(360-40)
400/400=320/320
1/1=1/1
1=1