An aircraft flying with the wind flies to new york in 4 hours, on the return trip, the plane takes 5 hours in the same wind, find the speed of the plane if the air is still.
+118609 An aircraft flying with the wind flies to new york in 4 hours, on the return trip, the plane takes 5 hours in the same wind, find the speed of the plane if the air is still.
Let the distance be d km
With the wind the speed is d/4 km/hour
Against the wind the speed is d/5 km/hour
so
P+w=d/4
P-w=d/5
add
2P=9d/20
P=9d/40
So the speed of the plane with no wind would be the distance in km * 9/40 km/hr
