A simple, yet mysterious demonstration of the physics of friction requires a test tube filled about ¾ with salt. On top of the salt, place a marble and then cork the top of the test tube. Explain to the students that you are going to make the marble travel through the salt from the top of the test tube to the bottom. Holding the tube vertically with the marble on the bottom, shake the test tube up and down. Because the salt is lighter, it has a greater "relative friction" and thus is slower than the solo marble. Each shake compresses the salt and allows the marble to rise upward.
Demonstrate the power of a static electric charge by running water out of a faucet, making certain the students can see it. The stream should be about 1/8 of an inch thick. Rub a balloon on a sweater or dry hair energetically to build up a static electric charge and then slowly move the balloon to the stream of water. The water, which is neutral, will be attracted to the charged balloon and "bend" toward it.
Another static electricity experiment conducted with a balloon will allow you to create light sparks inside a fluorescent tube. Turn off the classroom lights and vigorously rub the balloon on a sweater or dry hair until it has built up a good charge. Touch various parts of the fluorescent light tube with the balloon to watch the small sparks appear. When it touches the tube, electrons pass from the charged balloon to the tube creating the small light sparks.
Demonstrate the strength of raw eggs by having a student walk on them. Remove the tops from about six or eight egg cartons filled with raw eggs, line them side by side in two rows, the rows a few inches apart. Have a student remove his or her shoes and socks and attach flat pieces of polystyrene to the bottom of the student's feet (small pairs of rolled duct tape on each polystyrene piece with the sticky side exposed will attach them to the student). Help the student balance as he carefully walks on top of the eggs. You can have a smaller student do this bare foot. The eggs should remain intact because the student's weight is dispersed over the eggs.