Question

An airplane flies with a velocity of 55.0 m/s [ 35o N of W] with respect to the air (this is known as air speed). If the velocity of the airplane according to an observer on the ground is 40.0 m/s [53o N of W], what was the wind velocity?

Answer 1

this about adding vectors.

The velocity of gthe plane relative to ground = velocity plane relative to air + velocity air relative to ground

You know 2 of those so you need the 'triangle of vectors to solve it:



above shows plane relative to air, and plane relative to ground