...cruises at 180 mph in calm air.? If the plane flies 7 miles with the wind in the same amount of time as it flies 5 miles against the wind, then what is the wind speed?
Similarly,
let x=plane speed=180
let y = wind speed
let t = time
since distance d = v*t
Downwind d = 180t+yt = 7
Upwind d= 180t -yt = 5
Subtract first from second eqaution
2yt=2
yt=1
plug into the first equation
180t +1=7
180t=6 so t = 1/30 (or 2 minutes)
plug into yt=1 y*1/30=1 so y=30 mph
(go downwind at 180+30 =210 mph for 1/30 hour = 7 miles)
(go upwind at 180-30 -150 mph for 1/30 hour = 5 miles)