Simple Machines

          Energy transfers are similar to the law of conservation of energy.  The conservation of energy states that energy is neither created nor destroyed.  There are several examples of energy transfers in our Rube Goldberg machine.  A model Porshe 918 Spyder, the first component of our machine, gains kinetic energy because of its increasing speed.  It hits a domino, which falls over into the next domino.  The car hitting the domino and causing the domino to fall over is an energy transfer.  Newton's first law is at work in this scenario.  The domino is an object at rest, but it is no longer at rest because it was acted on by an external force, which is the model car.

          By the end of the domino chain, a tennis ball is knocked off of its platform by the last domino.  The kinetic energy of the last domino is transfered to the tennis ball through impact by changing the tennis ball's state from potential energy to kinetic energy.  The ball transfers that same energy into the first class lever that it falls on as the input force.  This kinetic energy changes direction from a downward fall to an upward motion through the first class lever.  This lever triggers the realease of the energy stored in a rubber band (spring), which pushes a small model of Lightning McQueen forward.  

         A final example that is found in our Rube Goldberg machine of energy transfers is when marbles are sent into and down a slender PVC pipe.  These marbles gain kinetic energy by falling first out of a basket, then down the tube, and finally into a small paper and duct-tape bucket.  All of this kinetic energy is transferred through a fixed pulley and eventually pulls out a rectangular piece of plywood.  This piece of plywood is suspending a small marble above a mouse trap.  Once the piece of wood is removed, the tennis ball will fall and transfer its kinetic energy to the mouse trap, which will cause a binder clip to close and squeeze toothpaste out onto a toothbrush.