5th Grade Science Fair Projects

One of the most absorbing 5th grade science fair projects is the tornado in a bottle. This is a classic experience and every child is sure to love it! It is advanced enough to impress any teacher or judge but it's also at a level that a ten-year-old child can understand.

What You'll Need:

• Two empty 2 litre plastic soda bottles
  
• One Tornado Tube plastic connector (you can find these in locations selling science tools, and novelty stores); You can also create your own using a washer for a faucet
  
• A few drops of food colouring (optional)
  
• Pieces of paper (optional)

Assembly:

Put water into one of the bottles, about 2/3 full. If using, you can add food colouring or bits of paper to the water. Connect the two bottles using the connector or washer but make sure the fit is comfortable and not too tight. Or connect the bottles by placing the washer between the tops and taping them together. Put the two bottles on a sturdy surface. Make sure the empty bottle is on the bottom.

The water will drip down into the lower bottle and at the same time, air bubbles will float into the top bottle. The water flow may stop completely. Again making sure that the empty bottle is on the bottom, move the bottles in a circular motion a few times. Again place the bottles on a sturdy surface. A shape, such as that of a tornado, can be observed. Notice the shape of the vortex. The flow of the water should also be observed as it drains into the lower bottle.

What's Happening:

When the water is still, the tension created on the surface creates a skin-like layer of water across the small hole in the centre of the connector. When the top bottle has water in it, the water will press against this surface to form a bulge, which then falls into the bottom bottle. As the water moves into the bottom bottle, the air pressure in that bottle builds and air bubbles are forced into the top bottle. The pressure placed on the surface in the connectore by the water lowers the top bottle empties. When the water level and pressure are both significantly low, the water surface can stop the flow and the water completely.

By rotating both bottles a few times, the water in the upper bottle starts moving in a circular motion. As the water is emptied into the bottom bottle, a tunnel forms. The movement of the water remains the same as it moves inward. The speed of water around the centre increases as it approaches the centre of the bottle.

To make the water move in a circle, forces called centripetal forces must act on the water. These forces are created by a combination of air pressure, water pressure, and gravity. As far as 5th grade science fair projects are concerned, this one will both interest and delight all who view it.

Note: See the Disclaimer before starting this project.