Magnetism

Magnetism An unseen force that attracts certain metals Magnetic Ex: Metals containing the elements Iron, Cobalt, Nickel Non-magnetic Ex: plastic, wood, glass, rubber

Attraction vs Repulsion Each magnet has a north and south pole Attraction: Opposite poles attract or pull toward each other Repulsion: Like poles repel or push away from each other

Three Types of Magnets Permanent – stays magnetized for a long time EX: Whiteboard Magnet Temporary – loses its magnetism after only a short time EX: Paperclip Electromagnets – a tightly wound coil of wire which acts like a permanent magnet when current is flowing in the wire EX: Electromagnet in a doorbell (any electronic device)

Magnetic Field

The Magnetic Field Every magnet has two poles (North and South) The magnetic field, or strength of the magnet, is concentrated at the poles The field exists in all directions but decreases in strength as distance from the poles increases Less distance = stronger magnetic force Less mass = stronger magnetic force

Examples of Magnetic Fields The Magnetic Field Earth’s Magnetic Field