Friday, February 5, 2010

Compass

Compass


Materials:
A magnet, a bowl of water, a needle.


Instructions:
Magnetise the needle by stroking it (Say 40 times) in one direction with the same side of a magnet each time. Place the needle on a small leaf (Or piece of tissue paper) and gently put on the surface of the water. If you use tissue paper it should soak up the water and sink leaving the needle on the surface! The needle will slowly turn to point North-South. You can also magnetise the needle by stroking it with silk in the same direction or by aligning it in a pre known north south direction and gently tapping it with a hammer on one end. If you are using it to get home, be careful, the pointy end of the needle may actually point South it depends which way you stroke it and with what end of the magnet is used. The four main points of a compass can easily be remembered by the term: Never Eat Shreaded Wheat (Placed clockwise)


Hints:
Common magnets are made of iron or steel and only attract iron or steel. The South side of a magnet will be attracted to the North side of another, but will repel the South side. The earth itself is an effective magnet where the North pole is located in Canada and the South pole is in the Indian Ocean just off Antarctica. It is these two poles that the opposite ends of the needle are being attracted to and that's why it always aligns itself in the same direction!




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