It's a Twister!

Make a model of vortex to help visualize what happens during a tornado.

What You'll Need

• 8oz. Jar with lid (wide mouthed jar is best)
• Water
• 1 tsp white vinegar
• 1 tsp clear dish soap
• Glitter

Directions

• Fill the jar ¾ of the way full with water.
• Add one teaspoon each of vinegar and dish soap.
• Sprinkle in a small amount of glitter.
• Screw on the jar lid tightly and shake vigorously to mix the vinegar, soap, and glitter.
• Set your jar on the table and allow the liquid to settle for a moment.
• Swirl the jar so that the liquids inside form a vortex.
• Stop swirling and observe. What do you notice about the glitter? Which part of your vortex is larger or smaller?
• Try it again - see how changing the amount of swirling affects your vortex. What else can you change?

What's Happening?

As you swirl the jar, the water that is against the glass is pulled along due to friction between the water and the glass. The water that is in the middle (not touching the glass) takes longer to get moving. But eventually both the glass jar and the water are spinning as you swirl. When you stop rotating the jar, the fluid in the jar keeps spinning. A mini twister can be seen for just a few seconds when the water on the outside of the vortex slows down and the water on the inside of the vortex continue to spin rapidly.