Answer:
Speed of wind = 50mi/hr, Speed of plane in still air = 400mi/hr
Step-by-step explanation:
Let the speed of the wind = Vw,
Speed of the plane in still air = Vsa,
The first trip the average speed of the plane = 1575mi/4.5hours = 350mi/hr
The coming trip the wind behind = 1575mi/3.5hrs = 450
Write the motion in equation form
First trip ( the plane flew into the wind)
Vaverage = Vsa - Vw
350 = Vsa - Vw
Second trip the wind was behind
450 = Vsa +Vw
Adding the two equation
800 = 2Vas
Vas = 800/2 = 400mi/hr
Substitute for Vas into equation 1
350mi/hr = 400mi/hr - Vw
Vw = 400-350 = 50mi/hr