An airliner flies 3,360 miles in 4 hours with the wind. On its return trip, it took 2 hours flying against the same wind to go 1,360 miles. What was the wind speed?
2007-07-05 10:11:38 · 12 answers · asked by *05* 1 in Science & Mathematics ➔ Mathematics
Let speed of the Plane=x
& that of the wind=w
Therfore (x+w)*4=3360
& (x-w)*2=1360
Or x+w=3360/4=840
x-w=1360/2=680
Or 2x=1520
Or x=760
Or w=840-760=80
Or wind speed is 80 miles
2007-07-05 11:38:18 · answer #1 · answered by MAHAANIM07 4 · 0⤊ 0⤋
distance = speed * time
let p be the speed of the plane
let w be the speed of the wind
when the plane travels in the same direction with the wind, the resultant speed of the plane is p + w. The trip takes 4hr to travel 3,360 miles
3,360 = 4(p + w)
when the plane travels against the wind, its resultant speed is p - w. The trip takes 2 hrs to travel 1,360 mile
1,360 = 2(p - w)
solve for w
1360 = 2(p - w)
680 = p - w
-w = 680 - p
w = p - 680
3,360 = 4(p + w)
3360 = 4(p + p - 680)
840 = 2p - 680
2p = 1520
p = 760
w = 760 - 680
w = 80 mi/hr
the speed of the wind is 80 mi/hr
2007-07-05 17:23:01 · answer #2 · answered by 7 · 0⤊ 0⤋
The wind speed was 80 mph. You figure the speed in MPH in each direction by dividing the miles by the hours. (840 with the wind and 680 against the wind). Then add the two flight speeds together and divide by 2 to get an average. In this case, the average speed is 760 MPH. Using the formula,
Average speed + X = 840 or Average speed - X =680.
2007-07-05 17:26:57 · answer #3 · answered by Anonymous · 0⤊ 0⤋
s = Speed w = Wind so Speed + the Wind for 4 hours = 3360 miles
(s+w) * 4 = 3360 so 4s + 4w = 3360 divide all by 4 = s + w = 840 so s = 840-w
coming back Speed - the Wind for 2 hours = 1360
(s-w) * 2 = 1360 so by substatution remember s=840-w lets put that in for s in
(s-w) * 2 = 1360 so (840-w-w) * 2 = 1360 or (840 -2w) * 2 = 1360 divide by 2 =
840 -2w = 680
-680 -680
160 -2w = 0
+2w +2w
160 = 2w now divide by 2
80 = w so the wind speed is 80 mph
2007-07-05 17:36:29 · answer #4 · answered by jeremeae 2 · 0⤊ 0⤋
wind at back: 3360/4 = 840 mph
into wind: 1360/2 = 680 mph
difference is 160 mph...
wind is 80 mph. The plane goes 720 (720+80 with wind at back and 720-80 into the wind)
2007-07-05 17:19:46 · answer #5 · answered by Dave 2 · 0⤊ 0⤋
With the wind his rate is 3360/4=840
Against the wind it is 1360/2=680
(840-680)/2=80
2007-07-05 17:19:20 · answer #6 · answered by Anonymous · 0⤊ 0⤋
80 mph wind speed
3360 divided by 4 = 840 mph one way
1360 divied by 2 =680 mph the other way
840-680= 160
divide by 2 = 80
2007-07-05 17:18:28 · answer #7 · answered by dpgoronzy500 2 · 0⤊ 0⤋
x= rate of plane w= rate of wind
(x+w)4 = 3360 --> 4x+4w = 3360
(x-w)2 = 1360 --> 4x-4w = 2720
So 8x = 6080
x = 760 mph
4w=3360-4x=3360-3040=320
w = 320 /4 = 80 mph
2007-07-05 17:25:56 · answer #8 · answered by ironduke8159 7 · 0⤊ 0⤋
80 mph
2007-07-05 17:19:27 · answer #9 · answered by psbhowmick 6 · 0⤊ 0⤋
well my calculations were x=760 ans y=80 so that means its 80 miels per hour
2007-07-05 18:21:44 · answer #10 · answered by redo 1 · 0⤊ 0⤋