Center of Gravity Paradox (LSE) Things are not always what they seem. Our angular momentum apparatus is weighted at one end. Try to balance the one meter rod with the heavier end down; intuition tells most people this should work. In actuality, the opposite is true - turn the rod over and balance it easily on a mere fingertip. This is a hands-on way to introduce the concepts of the center of gravity, angular acceleration and moment of inertia. Mass is movable. Instructions include theory. Qty :