Fry gun

One to definitely build at home too! You need a hollow tube, and a narrower full tube that fits inside the hollow tube. Make sure there is a piece of potato in your hollow tube along the front and back. This way, you block the escape route of the air inside the tube. Now when you push the narrower tube in, you push the gas particles closer and closer together and the pressure in the tube builds up. Because of that increase in pressure, the fries shoot out of your gun at the front.