Magnets

1
Magnets

• Investigation 1 Review

2
Stuck on Magnets

• Magnets stick to some metals, but not all metals.
• Magnets stick only to items that are steel or
  iron.
• Magnets do not stick to aluminum.

3
Forces Attract and Repel

• Opposite poles of a magnet attract, or pull
  together, as seen in the top magnets in the
  picture.
• Like poles of a magnet repel, or push apart, such
  as the magnets at the bottom of the picture.

4
Magnetic Detectors

• Compasses can be used as detectors because the
  needle of the compass will always point toward
  the magnets force.
• Other good detectors are iron filings, metal
  screens, and paper clips.

5
Induced Magnetism

• When magnetic force travels from a magnet through
  a metal item, the metal item can become a
  temporary magnet as long as it continues to touch
  the magnet.
• The nail below is a temporary magnet.

6
Breaking the Force

• As the distance between two magnets increases,
  the force of magnetism decreases, and it is
  easier to break the force.
• The force is much stronger when the magnets are
  close together.

7
Time for a QUIZ!

• Which of these items will NOT stick to a magnet?
• Steel nail
• Paper clip
• Aluminum foil
• Penny
• A and B
• C and D

8
FA magnet does not stick to materials that
dont have steel or iron in them, such as a penny
or aluminum foil.
9
If two magnets are placed end to end with the
same poles touching.

• The magnets will attract.
• The magnets will repel.

10
BLike poles will repel each other.
11
Which of these items would NOT be a good detector?

• Penny
• Compass
• Iron Filings
• Paper Clip

12
AA penny does not have iron or steel in it, so
it could not detect a magnet.
13
Why does the paper clip stick to the nail?

• Force of Repulsion
• Force of Attraction
• Magnetic Field
• Induced Magnetism

14
DInduced magnetism can create temporary
magnets from items with steel or iron, as long as
the item remains in contact with the magnet.
15
Breaking the Force

• What happens to the force of magnetism as the
  distance between two magnets increases?
• The force gets stronger.
• The force gets weaker.
• Nothing happens to the force.

16
BThe force is weaker when there is a greater
distance between the magnets.
17
May the force be with you. ?