An essential part of projectile studies is the "monkey and hunter" problem. An elastic powered "gun" 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. Both monkey and bullet fall at the same rate and the bullet always hits the monkey regardless of how far away the monkey is. The system has everything required except a low voltage smoothed  power supply and laboratory stand for the electromagnet.