This Monkey and Hunter apparatus demonstrates the equation of motion and projectile theory. The 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.It is recommended that the solenoid which is rated at 6V maximum is powered by a Smoothed D.C. Variable Power Supply or a 4.5V Battery. The Retro Regulated PSU is suitable for this.Associated Products:G-Clamp - to secure the gun unit to the bench - B8R06357Retro Regulated PSU - B8R04367Retort Stand Bundle - B8R06571