- Rub a light-weight iron needle with a magnet 50 or so times.
- Stick it through a thin piece of Styrofoam.
- Set the whole business afloat in a bowl of water and observe how, try as you might, you cannot prevent the needle from pointing along a north-south axis.
Thursday, December 11, 2008
Physics: Making Magnets
Last week the kids discovered that iron-containing metals can themselves becomes magnets if they are rubbed by a magnet. We used this observation to build compasses in 3 easy steps: