Several empty yogurt cartons, with lids
A pair of short-bladed scissors
A smooth surface like a table or countertop
An adult's permission to use the scissors
Draw a small circle in the center of the bottom of the yogurt carton. Carefully cut out the circle with the scissors.
Scatter the confetti on the table or countertop, covering an area about the size of a dinner plate.
Hold the carton so the end with the hole is above the scattered confetti. Tap the lid with your fingers. You should see the confetti move. If not, tap harder or hold the carton closer to the confetti.
Why does it work?
When you tap the lid, it bends into the container. When it bends, it pushes some of the air inside the container out of the way. The displaced air escapes through the hole in the bottom of the carton and moves the confetti.
Vary the shape and size of the holes in the bottom of your yogurt cartons. Which moves the confetti farthest? Which moves the most confetti? Why? Can you still move the confetti if you remove the entire bottom of the carton?
Summer Science Potpourri isprovided as a public service by the University of Alaska Fairbanks, in conjunction with the College of Natural Science and Mathematics. For more information, contact Marmian Grimes at (907) 474-7902 or via e-mail at firstname.lastname@example.org.