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Activity Time: 15 minutes
Recommended Grades: 1 - 8
Objectives: In this activity, we will model and understand the movements which create tornadoes. We also will be able to analyze the relationship between the size of a tornado and its speed.
As you move the jar in a circular motion, the fluid against the glass is being pulled into motion through friction. The fluid toward the center of the jar is slower to begin moving.
Eventually, all the water moves at the same speed. When you stop rotating the jar, the fluid continues to move. A vortex can be seen when the outer fluid slows down, but the inner fluid continues to spin quickly. In nature, this rotation occurs when there is a change in speed and direction between two different streams of wind. This is called “wind shear,” and causes a rotating column of air. If this column is caught in a supercell thunderstorm, the spin and speed of the column increases, and a tornado funnel cloud forms.
Looking for even more "Tornado in a Jar" fun? Check out this episode of My Pet Is My Lab Partner, where Fred Hartmann, Director of Guest Programs at LSC, and his lab partner, Colonel Quail, conduct the experiment themselves: