Newtonian Demonstrator, 1 Each

The Newtonian Demonstrator by United Scientific is a classroom apparatus for illustrating Newton's Third Law of Motion and the principle of conservation of momentum. Five polished metal balls hang on thin bifilar suspensions from a support designed for stability, so the balls stay aligned and collisions repeat cleanly. Physics teachers use it for momentum and energy conservation lessons at the front of the room or on student benches.