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WOW !. Magnet Magic. Magnetic materials are attracted by magnets. A paperclip is attracted to the ends of a bar magnet. The paperclip is made of steel. The arrow shows the force on the paperclip. Representing forces with arrows. The magnet also is pulled towards the paperclip.
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WOW ! Magnet Magic
A paperclip is attracted to the ends of a bar magnet • The paperclip is made of steel. • The arrow shows the force on the paperclip.
Representing forces with arrows • The magnet also is pulled towards the paperclip. The two forces are the same size and in opposite directions.
2 magnets • These ends attract • These ends push apart – (repel) There are two sorts of magnetic poles.
N S Making a compass • When a magnet is hung up one end will point North. • so it lines up North/South • The same end always points North • The end that points North is called the north seeking pole
NORTH POLE The Earth is a magnet
Using a compass to find directions • A compass needle always points to the Earth’s North Pole. • Some birds use the Earth’s magnetism to find directions.
S N A magnet has a north pole and a southpole.
S S S S N N N N The north pole attracts the south pole of the other magnet.
S N N S The north pole repels the north pole of the other magnet. • You can feel the magnets pushing apart. • This is called repulsion Note - south poles also repel each other
Something very new! • A computer that will stay booted up when you switch it off – it will be on sale in a few year’s time. • It will have memory called MRAM and use special magnets ! (Magnetoresistive Random Access Memory)
What have we learned? • Magnets will attract magnetic materials • iron and steel • Magnets have two sorts of poles • north and south • Magnets repel each other as well as attract • similar poles repel • opposite poles attract • A compass is a little magnet • The Earth is like a magnet • compasses are used to find directions • Special magnets are used in computers
It moves! • A motor causes movement. • An electric current and a magnetic field can make a simple motor. magnet + electric current movement
Spot the motors Can you think of other examples?
Very tiny motors can be made • When the drawer for a CD opens and closes a tiny motor makes it move • A tiny motor moves the camera lens when the camera is switched on • Many small toys have motors in them • robots, • Artificial limbs can use tiny motors to act like muscles
Magnets are amazing! Magnets + electric currents make things move!