The angular momentum can be in a different direction than the angular velocity - but in this case, I is not a scalar quantity. Here is the short scoop on the angular momentum principle.

The lift force is proportional to the square of the ball’s velocity and acts perpendicular to this velocity and to the angular velocity vector ...

Before the car moves, the angular momentum of the Earth plus cars is: (magnitude only since the direction does not change) Since the cars have the same angular velocity as the Earth, I can add the ...

Write out the angular velocity vector ω in terms of the two components described above. Take a time derivative of ω to get the angular acceleration α of the bar. When taking this derivative, you will ...