With a head wind, it takes 7 hours to fly 2800 miles from miami to seattle. with a tailwind, and the same airspeed, it takes 5 hours to fly in the opposite direction, from seattle to miami. find the airspeed and the windspeed
2800 / 7 = 400 mph - its speed from Miami to Seattle
2800 / 5 =560 mph - its speed from Seattle to Miami
[560 + 400 ] / 2 =480 mph - its speed in still air.
[560 - 400 ] / 2 =80 mph - the speed of the wind.
+128475 Call the windspeed, W
Call the rate of the plane in still air, R
And
With the wind the effective rate is R + W
Against the wind the effective rate is R - W
And we know that distance / rate = time ....so....
2800 / (R + W) = 5 2800 / (R - W) = 7
2800 = 5 (R + W) 2800 = 7 (R - W)
2800 / 5 = R + W 2800/7= R - W
560 = R + W 400 = R - W
Add the last two equations and we get that
960 = 2R
480 = R
And
560 = R + W
560 = 480 + W
80 = W
