Hello, Solid8Snake!
A plane goes from city A to city B. In a Cartesian plane.
City A is at the origin and city B has coordinates (100,150).
If there is no wind, the flight lasts one hour. Unfortunately, there is a wind.
If the pilot does not adjust his flight path, he will be at point (120,160) after an hour.
What is the speed of the wind? Code:
 C
 o(120,160)
 * *
 * *
 * *
 * *
 * *
 * o(100,150)
 * * B
 * *
 * *
A *                   

The plane's original vector was: .
Due to the wind, , it flies to
Since , we have: .
. . Hence: .
The wind's vector is: .
Its speed (magnitude) is: .