Magnets

MagnetAn object that pulls

certain metals towards it.

Magnets• A magnet has a

force.• A force is a push

or a pull.

MagnetismMagnetism is a force that makes a magnet able to push or pull another object

Types of Metals that are attracted…INCS

I.N.C.S.Iron

NickelCobaltSteel

A rock…magnetic?.

lodestone is a rock that occurs in nature

and is magnetic

Magnetic Fieldspace around a

magnet where the force of the magnet

can still work.

Magnetic FieldImage From: http://www.bbc.co.uk/schools/ks3bitesize/science/images/magnetic_fields.gif

Magnetic Poles.

areas of the magnet where a magnet’s attraction is the

strongest

North and South

Magnets have two ends, they are also called poles. The poles are named North and South.

Attract•A magnet attracts certain metals

Attract

To Pull TogetherS N S N

Repel

To push apartS N N S

2 Types of Magnets.

• Temporary Magnet – an object that loses its

magnetism after a short time

• Permanent Magnet- an object that keeps its

magnetism for a long time

Compasses

This device shows

direction

CompassesA compass works because Earth is surrounded by a magnetic field.

Compasses

North on a compass is attracted to

Earth’s Magnet

Magnets are Everywhere

RefrigeratorsCars

Heavy machinery

North and South

N

N S S

Repel or Attract

S N N S

S N S NRepel

Attract

Different Kinds of Magnets

N

N S S

Bar Magnet

Horse

sho

eMag

net

Review (What kind of magnets are these?

N

N S S

Bar Magnet

Horse

sho

eMag

net

Earth is a Magnet

•Earth is like a magnet because it has melted iron (molten)deep inside

Earth is a giant bar magnet

Earth’s Magnetic Field

Image From: http://oceanexplorer.noaa.gov/explorations/05galapagos/logs/dec22/media/magfield_600.gif

Magnetic or Not

ReviewMagnets have 2 _______.

What 4 types of metals do magnets attract?iron, nickel, cobalt, and steel

poles

Magnets attract _____________.metals

ReviewWhere are some places you can find magnets?

How does a compass work?The magnet on the compass is attracted to Earth’s magnet

refrigerators, can openers, machinery, etc

Earth is like a giant __________.magnet

ReviewTo pull together is to ______.

Can 2 like poles pull together?No

attract

To push apart is to ______.repel

ReviewCan two opposite poles pull together?

What are the end points on a magnet called?poles

yes

Why is the earth like a giant magnet?is has melted iron inside

ReviewWhat is molten?

Where is a magnet the strongest?at its poles

melted iron

Which object is not magnetic? steel nail, iron lock, plastic glass

plastic glass

ReviewWhy does a compass always point north?

What is the name of a magnetic rock?lodestone

because its magnetic needle is attracted by the magnetic force given off by Earth’s North Pole

What do we call magnets that lose their magnetism after a short time?

temporary magnet