Did you know that your cereal may be magnetic? Depending on the brand of cereal you enjoy in the morning, you’ll be able to see the magnetic effects right in your bowl. You don’t have to eat this experiment when you’re done, but you may if you want to (this is one of the ONLY times I’m going to allow you do eat what you experiment with!) For a variation, pull out all the different boxes of cereal in your cupboard and see which has the greatest magnetic attraction.
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Materials:
- a bowl of cereal with milk
- spoon
Download Student Worksheet & Exercises
- Fill the bowl with milk.
- Put about 20 pieces of cereal (not the whole box!) into the bowl.
- Stir up the bowl a little and watch what happens.
If you watched carefully, you saw that as the cereal “O’s” got close to one another, they attracted each other. The closer they got, the stronger was their attraction to each other and the faster they moved towards each other. If you wait and watch long enough, you get a nice tight batch of cereal all clustered together in one or two big blobs. This activity is a great illustration of what is meant by the inverse square law because the attraction between “O’s” was stronger the closer they got to each other.
I discovered this activity one morning as I was eating cereal. The same thing happens with bubbles when you’re doing the dishes. Science is everywhere! Feel free to eat the cereal!
Exercises
- Why do the pieces of cereal stick to each other?
- Does the cereal move slower or faster the closer the pieces come in contact with each other?
- What other cereals does it work for?
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We completed this experiment and concluded that our cereal is not attracted to each other because of magnetism. Instead it is moving to each “O” because of the meniscus becoming concave around the “O’s” and pulling surrounding “O’s” toward them. Magnets did not repel nor attract our “O’s.” We noticed the cereal moving toward the magnet if we accidentally dipped the magnet slightly into the water. This further backed up our conclusion that we were creating a dip in the surface of the water and causing the meniscus under the magnet to bend inward, thus pulling the cereal into the dip.