Science Buddies: "Ask an Expert"

Good Morning,

Please help!! i would like info on comparing the strength of bar, disk ring, horseshoe and cow magnets with paper clips. Time is running out.

Thank you kindly,

Hi,

Here is a Science Buddies project about building a Hall effect gauss meter and using it to measure the strength of magnets:

https://www.sciencebuddies.org/science- ... p030.shtml

Here is a second project that measures the variation in magnetic strength with temperature by checking the number of paper clips the magnet can lift:

https://www.sciencebuddies.org/science- ... p025.shtml

Hope this helps.

Best regards,

Barrett Tomlinson

Please help,
My 4th grader daughter is interested in this experiment. we tried it by counting the clips in the room temperature, then we tried to heat the magnet for 15 minutes on the stove in boiling water for 15 minutes, it didn't work, then for 20 minutes, but it was still holding a lot of clips, maybe more than the other one in the room temperature! also we put another one in a cup of water in the freezer for 15 minutes, but same result! how can I heat the magnet to loose a good amount of its strenght, and should I put it in water in the freezer or put it by itself, and for how long. the due date for submitting the project idea is Monday, 01/24/11....Thanks

The typical temperatures required are in the hundreds of degrees C to see any large effect on the materials used in most commercial magnets. The fact that you saw a change is great.

The Curie Temperature http://en.wikipedia.org/wiki/Curie_temperature is the point at which magnetic properties disapear completely is listed for several materials.

Try running an experiment in an oven to determine how many clips drop off as the temperature is raised from room temperature to 450 degrees F.

is there a specific magnet we should get, or any kind would work?
thanks

Hi Liliane,

It seems that, according to one of the previously mentioned projects, five to ten permanent iron magnets that are all equally sized and equally strong should be good.

Hope this helps,
RM