Question 623037
an airplane makes a 990 km flight with a tailwind and returns, flying into the same wind.The total flying time is 3hrs 20 mins and the airplanes speed in still air is 600 km/h
what is the speed of the wind.
**
let x=speed of wind
600+x=speed of plane with tail wind
600-x=speed of plane into wind
Total flying time=3hr+20min=20+1/3 hr=10/3 hr
Travel time = distance/speed
..
990/(600+x)+990/(600-x)=10/3
LCD:3(600+x)(600-x)
3*990(600-x)+3*990(600+x)=10(600+x)(600-x)
3*990(600+x+600-x)=10(360000-x^2)
(3*990*1200)/10=360000-x^2
356400=360000-x^2
x^2=360000-356400
x^2=3600
x=√(3600)
x=60
speed of wind=60 km/hr