By Mosharraf Hossain

Tamara ShorterJohn 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.

ButtonYarn

Nuts & BoltsScissorsMarblePennyPaper ClipPencil

NoYesItem

What will make a magnet move?

Button

Yarn

Nuts & Bolts

Scissors

Marble

Penny

Paper Clip

Pencil

NoYesItem

Will these items be attracted to a magnet?

yes yes yes

yesyesyes

NO No NO

no

no no

The power of magnetic interaction.

N S

Were you correct? Why were these things attracted to the magnet?

SN SN

SN S N

What will happen when the ends of the two bar magnets are placed close together?

What will happen when the ends of the two bar magnets are placed close together?

N NS S

SN S N

The North and South poles of the magnet are attracted to one another.

Like poles of the magnet are not attracted, or repel one another.

What is magnetism?• Magnetism is the force of

attraction between magnets and magnetic objects.

Graphic Organizer (K W L H Chart)What We Know What We Want to

LearnWhat We Learned How Can We Learn

More

 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.

How do the magnets stick together?

What happens when you break a magnet?

How do magnets make things move?

  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?

  BY doing hands on activities.

Reading more books.

Magnetic Field LinesMagnetic 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/watch?

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 Number of Nail Number of wrapes Paper clips picked up1st turn 2nd turn 1st turn 2nd turn 1st turn 2nd turn 1st turn 2nd turn

Group 1 0 2 1 1 0 15 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

0

5

10

15

20

25

30

351s

ttu

rn2n

dtu

rn1s

ttu

rn2n

dtu

rn1s

ttu

rn2n

dtu

rn

1st

turn

2nd

turn

Numberof

Batteries

Numberof Nail

Numberof wrapes

Paperclips

Variables

Ran

ge

Group 1

Groput 2

Group 3

Group 4

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.

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 magnetismhttp://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

Magnetic Forces Scavenger Hunt

Additional Online Resources• 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 washerUses magnets in its pump and agitator timer.

The clothes dryer Uses magnets in its timerand 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.