500
A plane is flying at 500 km/h East, when it encounters a 100 km/h North crosswind (a wind that blowing at a right angle to the plane's direction). Does the crosswind make the plane move faster, slower, or is the plane's speed unaffected?
The plane moves faster because of the crosswind. Not only is it moving East at 500 km/h, but it is ALSO moving North at 100 km/h.