Magnetic Lines of Force

This website is a hands-on student investigation.  This site explains why the iron fillings attract the magnet and creates the magnetic field. Information about cow magnets and why they are used is also covered on this site. Trouble shooting about rusting of the iron fillings are also enclosed. This activity will allow students to see magnetic forces. This activity allows students to create and discover how magnets attract iron. Materials are easy to obtain. Teachers may want to make bottles ahead of time according to the level of their students. The visual representation of model will provide a wonderful opportunity for students to discover magnetic fields. The following url address contains several simple activities covering magnets http://www.exploratorium.edu/snacks/iconmagnetism.html

Weblink address (URL): 
Magnetic Lines of Force

Lesson Variations

Blooms taxonomy level: 
Applying
Extension suggestions: 

Going Further:
Cow magnets are strong, permanent magnets made out of alnico, an iron alloy containing aluminum, nickel, and cobalt. These magnets are available at most feed stores.
Ranchers feed these magnets to their cows. The magnet settles in the cow’s first stomach. When the cow accidentally eats bits of steel or iron, the magnet attracts the metal bits and holds them in its first stomach. If the sharp pieces of metal were to pass through the cow's digestive system, the animal would suffer what ranchers call “hardware disease.”

Helpful Hints

Tools and Materials:

  • A 16-ounce (0.5-liter) plastic water bottle or soda bottle
  • Iron filings (available at science museums or from scientific suppliers, or you can use magnetic sand—black sand—collected by dragging a magnet through iron-rich beach sand)
  • A plastic test tube that fits into the mouth of the bottle and is about 75% as long as the bottle is tall
  • Masking tape
  • A cow magnet or other cylindrical magnet that fits into the plastic tube (a stack of button magnets will also work)

References

Contributors: 
Rhilda Gastineau
Originator: 
Ayers Institute for Learning & Innovation