We took the jar with the rubber ball buried in the rice and shook it back and forth for a few minutes.
|
The ball popped up out of the rice!
|
 When we opened our can of Mixed Nuts there were four Brazil nuts visible on the surface. We closed the can and shook it back and forth for a few minutes as we did with the jar that had the rubber ball buried in rice.
When we opened the can there were five Brazil nuts visible on the surface.
As we ate the nuts we found a total of ten Brazil nuts in the can. When we got toward the bottom we found mostly peanuts.
The Brazil nuts are considerably larger than any of the other nuts in the mix. Like the rubber ball in the jar of rice they tend to rise to the surface when the container is shaken.
 |
The can of mixed nuts contained
Brazil nuts, cashews, almonds,
filberts, and peanuts. |
There was most likely a whole lot of shaking going on while the nuts were being transported by truck or train from the factory where they were canned to the store where they were sold. That's probably why there were already four of them on top even before we shook the can.
|
In Stratification & Segregation Hernán Makse shows how sand grains of different sizes and shapes may naturally separate after being thoroughly mixed together. See if you can figure out how to unmix these mixtures. Use any strategy you want to and any equipment and materials that you need.
Mix together 25 grams of salt and 25 grams of sand in a small jar. Now separate them. See how close you can come to getting back 25 g of each.
Now try 25 g each of sand and iron filings.
How about all three at once?
Let's throw in some sawdust to make it more difficult.
This one was suggested by Robert Krampf* as one of his many "Experiments of the Week". Mix together salt and ground pepper. How can you separate them?
Share your strategies and results.
|
Things To Do
Science
Center
Schools
SEED People
