ROLL A CAN WITH STATIC ELECTRICITY

* An empty soda can * blown-up balloon * A head of hair 1. Place the can on its side on a flat smooth surface like a table  or a smooth floor. 2. Rub the blown up balloon back and forth through your hair  really fast. 3. Now the fun part - Hold the balloon close to the can  without actually touching the can. The can will start to roll  towards the balloon without you even touching it!Try This Too:  While you've got the balloon out, tear up part of a tissue into  tiny pieces about 1/4 inch (.5 cm) big. Rub the balloon in your  hair again and bring it close to the tissue pieces. They will be  attracted to the balloon and then jump away.   This works a lot like our bending water experiment. When  you rub the balloon through your hair, invisible electrons  (with a negative charge) build up on the surface of the balloon.  This is called static electricity, which means "non-moving  electricity" The electrons have the power to pull very light objects  (with a positive charge) toward them - like the soda can.   The project above is a DEMONSTRATION. To make it a true  experiment, you can try to answer these questions: 1. Does the size of the balloon change the power of the pull? 2. Does the length of the persons hair effect the power of the  static electricity? 3. How much water can you put in the can until the balloon can't  pull it anymore?