You'll need two magnets for each project. Although there are other sizes of ring magnets, it can get expensive to buy them for a group. I found a source for ring magnets for as little as 10 cents U.S. per magnet (500+), but good prices even at smaller quantities. There is a $30 minimum order. http://www.allmagnetics.com/ceramicrings.htm or 1-800-262-4638. If the link becomes inactive, please let me know so I can find another source.
Or you might be able to find the magnets locally. I found them in a surplus/discount tool store.
Almost all of the flexible straws for sale in grocery and department stores are about 1/4" diameter. They fit into the middle of the magnets, allowing them to slide freely.
I find that pieces about 1" by 3" work well. Any size paper is OK as long as it can be taped to the magnet as shown in step 3.
This project will be over all too soon. There are a million things kids can do with 2 magnets, so I always let them play with them a few minutes before we get started. I suggest a few activities in the exploration page.
I suggest kids draw kangaroos, frogs, rabbits, etc., but the kids have drawn snakes, bears, mice, whales, penguins and pandas that seem to bounce just fine. They can cut out the figure if they want to, but it doesn't affect the project.
Young kids will need help or need to have it done for them. Cut a piece of tape long enough to go all the way around the magnet. Stick it on the bottom of the paper, centered, as shown.
Tape it on. The tricky part is to tape it securely without blocking the hole in the magnet. Obstructing the magnet hole would keep it from sliding up and down on the straw. An illustration shows the tape starting to be wrapped around the magnet (drawn with dashed lines to indicate it is hidden by the paper). The picture beside shows after the tape has been wrapped around.
The plain magnet, without anything taped to it, slides on first. It should stop when it hits the flex part. Now slide the magnet with the creature on. It will either bounce and float when it gets near the other magnet, or it will stick to it. If it sticks to it, take both magnets off, flip the bottom magnet over, and it will work.
Finally, stick some tape to the top of the straw so the magnets don't drop off and get lost.
I suggest you explain to the kids about not to get the magnets near audio or video tape, floppy or zip disks or credit cards. Magnetically stored data can be destroyed by magnets. Send a note home informing the parents, too. CDs and DVDs are not affected because they are optical, not magnetic.
|For explanations, activities and cool links related to magnetism click here or on the picture.|