Have you ever wondered how magnets work? Students explored the reach of magnetic fields, which is a space where the effect of one magnet can be felt by other magnets.
After discussing magnets, students were challenged with designing a device that could pass over a surface and detect hidden magnetic fields. Students worked in small groups of 2-3 students. Each group was presented with a box that had several magnets attached to its inside. Students were not able to observe the positions of the magnets with their eyes because the box stayed closed at all times. The box top was covered with a sheet of paper that has a labeled grid drawn on it (think of the game Battleship or a paper map). Each group chose from a variety of materials (cups, string, paperclips, clothes pins, pipe cleaners, nails, pennies, aluminum foil, plastic building pieces, and safety pins) with which they built their magnet detectors. Once building is complete, each group mapped out the locations of the magnets in its box by recording data on a coordinating worksheet. The students’ ingenuity came out as they successfully found all the magnets. Along the way they found that not all of the materials provided are magnetic, even though some are made of metal. It provided a great way to experience the “redesign” part of the engineering process.
Additional Information: Try this at home! If you have a sewing needle and a relatively strong magnet, try to align the crystal domains (mini-magnets) of the sewing needle by stroking it with the magnet repeatedly in one direction. Then see if the needle exhibits any magnetic behavior (repelling or attracting other magnetic objects.) http://www.scientificamerican.com/article/find-magnetic-north-with-compass-bring-science-home/