Download Ed 713.22 Magnet Power Point Presentation 2.1

By
Mosharraf Hossain
Tamara Shorter
John Heyenga
Ed 713.22/ Summer ’08
Which items a magnet will attract?
Test the items listed below and
record your answers in your Book.
Next slide will reveal answers.
Yes
No
Item
Pencil
Paper Clip
Penny
Marble
Scissors
Nuts & Bolts
Yarn
Button
What will make a magnet move?
Item
Pencil
Paper Clip
Penny
Marble
Scissors
Nuts & Bolts
Yarn
Button
Yes
No
Will these items be attracted to a magnet?
yes
NO
yes
no
yes
No
yes
yes no
yes
NO
no
The power of magneti
interaction.
Were you correct? Why were these things
attracted to the magnet?
N
S
What will happen when the ends of the two
bar magnets are placed close together?
N
S
N
S
What will happen when the ends of the two
bar magnets are placed close together?
N
S
S
N
The North and South poles of the magnet are
attracted to one another.
N
S
N
S
Like poles of the magnet are not attracted, or
repel one another.
N
S
S
N
What is magnetism?
• Magnetism is the force of attraction
between magnets and magnetic objects.
Graphic Organizer (K W L H Chart)
What We Know
They stick to
refrigerators.
They stick to
metals.
Sometimes they
won't stick to
each other.
They come in
all sizes and
shapes. We use
them to hold
papers. They
can hold a lot of
stuff. Some
ends stick to
each other.
Some magnets
have an N and
an S on their
ends.
What We Want to
Learn
How do the
magnets stick
together?
What happens
when you break
a magnet?
How do
magnets make
things move?
What We Learned
Why do they
stick to
refrigerators?
What metals do
they stick to?
Why do some
ends push
away from each
other? Why are
the ends called
poles? How do
opposite poles
react to each
other? How do
the same poles
react to each
other? How do
we use
magnets in our
homes?
How Can We Learn
More
BY doing hands
on activities.
Reading more
books.
Magnetic Field Lines
Magnetic field lines describe the structure of
magnetic fields in three dimensions. They are
defined as follows. If at any point on such a line
we place an ideal compass needle, free to turn in
any direction (unlike the usual compass needle,
which stays horizontal) then the needle will
always point along the field line.
Field lines converge where the magnetic force is
strong, and spread out where it is weak. For
instance, in a compact bar magnet or "dipole,"
field lines spread out from one pole and converge
towards the other, and of course, the magnetic
force is strongest near the poles where they
come together.
Magnet and Magnetic Field
Electromagnet
• A temporary magnet
made by passing
electric current
through a wire coiled
around an iron bar.
Use link below to see a
example of how to
make a temporary
magnet.
http://www.youtube.com/watc
h?v=gltbfUOf6F0
• A junkyard is one place to see
an electromagnet in action. A
crane holding a huge
electromagnet can be used to
pick up scrap metal when
current flows through it. When
the crane operator wants to
drop the scrap, he or she will
simply shut off the current to
the electromagnet.
Students’ results of
electromagnetic testing
Results of Electomagnetic test
Number of Batteries
1st turn
2nd turn
Group 1
0
2
Number of Nail
1st turn
2nd turn
1
1
Number of wrapes
1st turn 2nd turn
0
15
Paper clips picked up
1st turn 2nd turn
0
6
Groput 2
1
1
1
2
10
10
2
4
Group 3
1
1
1
1
15
30
3
4
Group 4
1
1
1
3
13
13
2
5
Results of Electromagnetic test
35
30
Group 1
20
Groput 2
15
Group 3
10
Group 4
5
Number
of
Number
Batteries of Nail
1st
turn
2nd
turn
0
1st
turn
2nd
turn
1st
turn
2nd
turn
1st
turn
2nd
turn
Range
25
Number
of wrapes
Paper
clips
Variables
What is the relationship between
electricity and magnetism?
Electricity and magnetism controls much
of our current technology (e.g. computers).
 Electricity and magnetism are linked
on a fundamental level.
Magnets are used to generate, or produce,
electricity.
Spinning a coil of wire inside a magnetic field
produces an electric force between the ends of
the coil.
In a similar way, an electric current produces a
magnetic field around it.
Magnetic Forces Scavenger Hunt
1) Write three questions for the class from this video.
Experimenting With magnets.
http://www.youtube.com/watch?v=Zfv-0bQtqaE&feature=related
2) Write three questions about different experiments that deal with earth's
magnetic force.
3) Examine the different photos and come up with two questions about Auroras.
The Auroras are connected to magnetic forces.
http://www.exploratorium.edu/auroras/index.html
A game about magnetic forces.
http://www.educational-games.org/logic_games/magnets.html
Write two questions for the class about what you observed.
Hunt for Magnetism: A treasure hunt on magnetism
http://www.kn.att.com/wired/fil/pages/huntmagnetisma.html
The scavenger sites as well as the treasure hunt site is located on the
filamentality website.
http://www.kn.att.com/wired/fil/pages/listmagnetisma1.html
Additional Online Resources
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Magnet Song
http://www.youtube.com/watch?v=G-nkIECIBWM
How does electricity create a magnet?
http://www.youtube.com/watch?v=emlzh9XXWgQ
Cartoons
http://www.youtube.com/watch?v=2vqgXRKHI-s
http://www.youtube.com/watch?v=I6VrCJRssKc
Mutual Distraction (Cartoon)
http://www.youtube.com/watch?v=4_5cztU9hVk
Underdog Cartoon
http://www.youtube.com/watch?v=jjX9vgT1rWw
http://www.youtube.com/watch?v=KFVhJX9RsGQ
http://www.youtube.com/watch?v=kQvv1V9z8uU
Magnet Quiz
http://library.thinkquest.org/06aug/02337/quiz.htm
Teaching magnets to students
http://www.youtube.com/watch?v=oypDGvBoKl0
Can you name something that is
huge and has
North and South Pole?
• If you answered “The Earth”, you were right!
• The Earth is a giant magnet. It has two magnetic
poles and it is also surrounded by a magnetic
field.
• This magnetic field is what causes the needle of a
compass to point in different directions and the
poles of a magnet to point either north or south.
The earth is like a giant magnet!
The nickel iron core of the earth gives the earth a
magnetic field much like a bar magnet.
What are magnets used for?
&
Why do we need to
learn about them?
Do you like roller coasters or
other amusement park rides?
• If you answered yes, then you should know that a roller coaster
mainly uses magnets to achieve quick acceleration at the
beginning of the roller coaster ride. The type of magnets used
in a roller coaster may vary, but the roller coaster depends
upon both the negative and positive abilities of magnets.
Computers use magnets on all of
these parts:
Cooling fans
Floppy disk spinner
CD spinner
DVD spinner
Hard disk spinner
Never put a magnet near a
computer or it will cause the magnets
inside the computer to mess up.
Magnets are used in factories
• Magna-Rails
Positioned under conveyor belts, Magna-Rails hold parts firmly
to the belt even at high speeds and on up or down inclines as
steep as 90 degrees.
Places, such as car manufactures, also
use magnets to carry heavy metal from
place to place.
What else are magnets used for?
The Refrigerator
Uses magnets in its compressor
and ice maker dumper. It also
uses magnets in the strip
around the door to hold the
refrigerator door closed.
The clothes washer
Uses magnets in its pump and
agitator timer.
The clothes dryer
Uses magnets in its timer
and drum turner
What else uses magnets?
A CD spinner, DVD spinner, and head positioner all
uses magnets. A Television has lots of magnets in it
along with a stereo system and speakers. These all
work by using magnets.
Without magnets, you would not
be able to….
• Use the microwave
• Have a dishwasher
• Have a furnace
• Use a credit card
• Hear the phone ring
• Or hear the door bell ring
All of these things use magnets to work!
Cont.
Without magnets, you would not
be able to….
• Post up your sports schedules on the
refrigerator
• Turn on the ceiling fan
• Use the electrical can opener
• Ride in a moving cars
(that’s right, cars have LOTS of
magnets inside to make them work!)
Magnets are all around us. Chances
are, if something moves with electrical
power, then it has a magnet in it
somewhere. How do magnets work
you might want to know? That is what
you are going to begin to learn about in
our magnet unit.