The angular momentum of a rotating wheel points along the axis of rotation.

Torque is a vector

A tangential push on the spinning wheel produces a

torque which causes the angular momentum to

increase

Gravity produces a torque which is perpendicular to the angular momentum

The change in angular momentum causes the gyroscope to precess

A bicycle wheel is hanging from a rope on one end of its axle, as shown. A person is holding the other side of the axle. What happens to the wheel

when the person lets go? How about now?