Note: This page shows how to make the project using east-to-get magnets (from Radio Shack). If you are making a project with a large group of more than 25, it becomes much cheaper (1/5 the cost) to order magnets by mail. Click here for instructions for a large group.
These are 1 1/8" diameter and come in packages of 5 for about $2.50 US as of this writing. You need two magnets for each project, so it will cost about $1 per project.
Many fast food places like Mcdonalds and Burger King have particularly wide diameter straws, probably so the thick shakes can pass through. They fit into the middle of the magnets, allowing them to slide freely. You will need as many as three straws per project. Although the straws are usually striped, I draw them as solid colors for clarity.
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.
The straw keeps one magnet on top of the other. If the straw is too small, the magnets get crooked. The project still works, but it's best to make the straw as fat as it can be, yet still have the magnets slide freely.
Even the straws from fast food restaurants are not quite fat enough. If you slice straws lengthwise with scissors, you can fit them over the un-cut straw, increasing the diameter. For my straws from Mcdonalds, two sliced straws fitted outside the un-sliced straw made it fat enough to keep the magnets from wobbling without getting stuck. You might have to experiment with the straws you get.
The illustration on the right shows an uncut yellow straw and a sliced pink straw fit over it.
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 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.
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.
|For explanations, activities and cool links related to magnetism click here or on the picture.|