Monkey and Hunter Launcher
This demonstrates the equation of motion and projectile theory. This apparatus allows for an interactive study of the problem by students. A spring powered rifle fires ping pong ball bullets at a model monkey supported from a small electromagnet. The electromagnet is switched off at the instant the projectile leaves the gun. No matter what the distance is between gun and monkey, the ball will always hit its target giving a dramatic demonstration of the fact that any projectile falls at the same rate regardless of its horizontal velocity.