11. Velocity Vectors 

Paul extends a televised classroom lecture on vectors to explain the resultant velocities of airplanes in wind.

End Question:

Suppose our airplane with a normal ground speed of 100 km/h is caught in storm where it encounters a 90° crosswind also of 100-km/h.  How fast will the airplane travel across the ground below? And another question: If the airplane changes course and flies directly into the 100 km/h wind, what will be its speed relative to the ground below?