As Seen on KONG on 5/14/2009 

Falling Lightning Experiment

Materials needed:

  • Bead necklaces
  • Cup or mug

Layer a strand of beads in to the cup so that they can flow without tangling. 
Gently pull the end of the strand over the side of the cup. The beads will start to cascade out of the container on to the floor. 

Explanation:  
The siphoning action of the beads happens because of acceleration due to gravity, and the weight of the strand as it falls from the cup. Each falling bead pulls the bead behind it. The momentum of the falling bead is strong enough to make the second bead fall. The momentum increases the leaping movement of the strand from the cup. As the strand leaps from the cup, it rises higher than the rim and seems suspended in the air. The highest point of this movement is called the crest. The entire strand will flow out of the container. Once started, a siphon requires no additional energy to keep going!

Tip for creating an extra long string of beads:
Go to an electronics supply store and buy shrink wrap tubing for electrical wires.  Butt two ends of strands together inside the tubing and then have mom or dad use a lighter to quickly heat all sides of the tubing until it shrinks around the beads, holding them together.

Stuffing the beads into the cup will result in a failed experiment, be sure to layer them in the cup.


Non-Newtonian Fluid

 Equipment:

  • 1 Cup of Corn Starch 
  • 2/3 Cup of Water
  • Shallow bowl or pie tin

Procedure for making it:

  • Place corn starch in the bowl or tin
  • Add water slowly, mixing the cornstarch and water with your fingers until all the powder is wet.
  • Keep adding water until the mixture feels like a liquid when you're mixing it slowly. Then try tapping on the surface with your finger or a spoon. When the mixture is just right, it won't splash but will feel solid. If your mixture is too powdery, add a little more water. If it's too wet, add more cornstarch. (it's easier to make a watery mixture more solid than the other way around)

Try bouncing a ball on the fluid, then let the ball sit there and sink.  Scrape up a section of the fluid and squeeze it, then let it rest in your hand and watch what happens.  Poke your finger in the fluid then try and pull it back out real fast.

Explanation:
Salt and sugar dissolve in water to form solutions. Cornstarch, however, does not form a solution with water. Instead, the cornstarch particles are held together by the water forming a mixture called a suspension. When pressure is applied, the particles jam, making it seem solid. Let go, and the particles in the mixture drift apart creating an ooze.

You can also add food coloring to the mixture to make it any color you like!