The momentum machine
demonstrates the concept of "angular momentum." The visitor stands on
a circular platform that can freely rotate. With a slight push, the
visitor can twirl around. The visitor immediately notices that the straighter
one stands, bringing body parts closer to the axis of rotation, the
faster one spins. Although "linear momentum" depends only on the mass
of an object and its velocity, the angular momentum also depends on
how FAR the mass is from the axis of rotation.