This topic has 0 replies, 1 voice, and was last updated 11 years, 5 months ago by Gary Williams. Author Posts 15 December 2010 at 13:44 #15410 This game can be used to explain the photoelectric effect. The work function is the amount of energy needed to remove the ball from the head; the rest of the energy is transformed into KE. Butt head game (£9.99 from Hawkin.com) or homemade Velcro equivalent, foam disc gun (£9.99 & £4.99) and an airzooka. Author Posts You must be logged in to reply to this topic.