The ground speed of the plane is 402 mph
We have given,
A plane leaves an airport traveling at 400 mph in the direction n 45° e. a wind is blowing at 40 mph in the direction n 45° w.
Now, Draw a right triangle with 400 and 40 as the two legs.
This is a right angle because 45 degrees NE is perpendicular to 45 degrees NW.
So, the two side lengths are 400 and 40
Using the Pythagorean theorem,
(a^2 + b^2 = c^2)
[tex]400^2+40^2=c^2\\\\c^2=160000+1600\\c^2=161600\\c=401.99[/tex]
Therefore the answer is 401.995, or 402mph.
To learn more about the speed visit:
https://brainly.com/question/4931057
