Magnetic Earth
Earth is a giant magnet, it has a north and south magnetic pole. The
force field extends thousands of miles into space. Earth can attract
many things and allows any magnet to swing freely. By using a compass
you can tell how far you are from the magnetic poles.
Make it work
Each magnet has two points called poles where the magnetic force is
strongest. The end of a magnet that points south is the south pole. This
is the basic principle that makes the compass work. Some compasses can
give very precise directions, but a simple compass will be fine.
To make a water compass you will need
- old yogurt container
- magnet
- needle
- slice of cork
- cardboard
- protractor
- tape
Procedure:
- Cut out a circle of cardboard and cut a hole in the center just
smaller than the opening of the yogurt container.
- Divide the circle into accurate quarters using the
protractor and label
the four compass points: North, South, East, and West.
- Make the needle magnetic by stroking it with one end of a magnet about
twenty times. Always stroke in the same direction. Tape the needle onto
a thin slice of cork.
- Fill the yogurt container with water and float the cork in it. When
the needle has settled to the north, tape the cardboard ring to the
container so that the needle points to the North label. Check your
readings against a real compass.
For two simple compasses you will need
- cardboard
- magnet
- tape
- needles
- wooden skewer
Fold a strip of cardboard and tape a magnetized needle to it.
Balancing compass
Create a cone from a semicircle of cardboard. Stick a wooden skewer or
toothpick into the top of the cone and balance the compass strip on the
end.
Jar Compass
Suspend the compass strip in a glass jar using a straw or a pencil and
some thread. This compass will also work outdoors because the jar
protects the needle from the wind.
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