This demonstration is more complicated because it involves a vector. For a rotating wheel, the direction of the angular momentum, , is found by curving the fingers of your right hand in the direction of the rotation, your thumb then points along . The angular momentum vector is perpendicular to the plane of the wheel. Sit on the rotating stool used in part II. Hold a bicycle wheel with its axis vertical. While the stool is at rest, have your partner spin the bicycle wheel. Carefully note the direction of spin of the wheel and of the stool. Give an explanation in terms of conservation of angular momentum. While the stool is still rotating, carefully turn the bicycle wheel upside down. Explain what happens.