Download Magnets - Lesson 1

What Is a Magnet?
Houghton Mifflin
Book F
Chapter 15
Lesson 3
Pages 62-65
Essential Questions
• Where do we find magnets in the
real world?
• Why does a magnet work
differently on various objects?
Pair Share: Take a few moments to discuss
these essential questions with your partner.
Main Idea
• A magnet is an object that
attracts certain metals.
• A magnet has a magnetic field
and magnetic poles.
Properties of Magnets
• What do you think would happen if you
placed a magnet on a refrigerator door?
• A magnet is an object that attracts
certain metals, mainly iron.
• This property of attracting iron and
certain other materials is called
magnetism.
• The force of magnetism on objects
decreases as the distance from the
magnet increases.
Q: Why Do Magnets Stick to
Most Refrigerators?
A: Magnets stick to most refrigerator doors
because the doors are made of steel, which
contains iron.
• Magnets do not attract most other metals or
materials such as plastic, wood, and rubber.
Magnetic Fields
• The space in which the force of a
magnet can act is called its magnetic
field.
• The force of a magnet is greatest at
two areas called the magnetic poles.
• On a bar magnet, and a horseshoe
magnet, the magnetic poles are at
the ends.
Bar Magnets
• When a bar magnet is allowed to
swing freely, one end always points
towards the north.
• The end of the magnet is the
north-seeking pole, or north pole.
• The other end of the magnet always
points south.
• This end is the magnet’s southseeking pole, or south pole.
Pair Share
• What will happen if you bring the unlike
poles of two magnets near each other?
• The unlike poles will attract each other
and pull together until they touch.
Earth as a Magnet
–Earth acts like a giant bar magnet
with two magnetic poles.
–Earth is surrounded by a magnetic
field with lines of force.
–The north-seeking pole of a
compass needle will turn until it
points toward the magnetic north
pole of the Earth.
Pair Share
• Question: How is Earth like a
magnet?
• Answer: Earth has magnetic poles
and is surrounded by a magnetic
field.
Your Task
• In your groups, make a poster to
share with the other groups of what
you learned in this lesson.
• Each member of the group needs to
share one thing they learned.
• You will share your poster with the
class.
• When you are finished, you can read
pages 62-65 in Book F.