Meaningful Applications Of Physical Sciences Dr. Michael H. Suckley Mr. Paul A. Klozik

MAGNETISM I. Teacher Notes A. Naïve IdeasNaïve Ideas B. Workshop ObjectivesWorkshop Objectives II. Building A Model of Magnetism III. Applying Magnetic Principles

MAGNETISM II. Building A Model of Magnetism A. Magnetic Nature of Matter Magnetic Nature of Matter Magnetic MaterialsMagnetic Materials B. Law of Magnetism Law of MagnetismLaw of Magnetism C. Magnetic Fields Mapping Magnetic Fields of A MagnetMapping Magnetic Fields of A Magnet Mapping Magnetic Fields of Like and Unlike Magnetic Poles Mapping Magnetic Fields of Like and Unlike Magnetic Poles.. 5 Mapping Magnetic Fields Using Iron Filings Mapping Magnetic Fields Using Iron Filings Analyzing Magnetic Fields Analyzing Magnetic Fields D. Structure Of Magnets Structure Of Magnets The Tube And Iron FilingsThe Tube And Iron Filings Applying The Model Of Magnetism To A Iron WireApplying The Model Of Magnetism To A Iron Wire E. Measuring The Force of A Magnetic Field Measuring The Force of A Magnetic Field

MAGNETISM III. Applying Magnetic Principles A. The Earth's Magnetic Field Determining Direction and The Earth’s Magnetic Field Determining Direction and The Earth’s Magnetic Field Investigating the Earth’s Magnetic Field Investigating the Earth’s Magnetic Field B. Relationship Between Electricity and Magnetism The Affect of Electricity Upon The Production of MagnetismThe Affect of Electricity Upon The Production of Magnetism The Affect of Magnetism Upon The Production of ElectricityThe Affect of Magnetism Upon The Production of Electricity C. Determining The Strength of An Electromagnet Determining The Strength of An Electromagnet D. Magnetism and Electric Motors Constructing An Electric MotorConstructing An Electric Motor

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Workshop Objectives 1.Determine which materials are magnetic and which are not. 2.Determine the Law of Magnetism. 3.Determine the geometry, or shape, of the magnetic field surrounding a magnet or a combination of magnets. 4. Describe the structure of a magnet. 5.Describe the Earth’s magnetic field. 6. Describe how the magnetic force of a magnetic changes with distance. 7. Describe the influence of electricity on the production of magnetism. 8. Describe the influence of magnetism on the production of electricity. 9.Describe the construction of a motor applying the magnetic principles learned in this unit. 8

Naive Ideas 1. All metals are attracted to a magnet. 2. All silver colored items are attracted to a magnet. 3. All magnets are made of iron. 4. The magnetic and geographic poles of the earth are located at the same place. 5. The magnetic pole of the earth in the northern hemisphere is a north pole, and the magnetic pole in the southern hemisphere is a south pole. 6.Larger magnets are stronger than smaller magnets. 7.Magnetic poles are always located at the ends of the magnet. 6

Magnetic Classification Materials Diamagnetic materials –these are materials that are not attracted to a magnet and are sometimes referred to as nonmagnetic materials. Paramagnetic materials – these materials are weakly attracted to a magnet, however, the attraction may be so weak it is not even noticeable. These are commonly referred to as nonmagnetic materials also. Ferromagnetic materials –these are materials such as magnetite, those do-dads and souvenirs we prominently display on our refrigerator doors, and any other materials that can be used to produce a “permanent magnet”. These are also the kinds of materials that are most strongly attracted to a permanent magnet. 2

Which Materials are Magnetic? Indicate by placing an Y or N for any magnetic materials found. MaterialMagnetic (Y/N)MaterialMagnetic (Y/N) 1. Lead 10. Wood 2. Steel 11. Rubber 3. Plastic Shot 12. Candy Topping 4. Colored Glass 13. Zinc 5. Aluminum 14. Gravel 6. Cobalt 15. Silver 7. Copper 16. Magnesium 8. Nickel 17. Tin 9. Brass

The Law of Magnetism 1.Obtain two unmarked magnets and one marked/reference magnet. 2.Adjust one of the unmarked magnets so that it is attracted to the S marked end of the reference magnet. Place a mark on the unmarked magnet indicating the attracted end. 3.Adjust the second unmarked magnet so that it is also attracted to the S marked end of the reference magnet; place a mark on the second unmarked magnet indicating the attracted end. 4.You have now identified (and marked) the ends of each ‘unmarked’ magnet. The ends that are now marked both behave the same with respect to the reference magnet. This means that the marked ends are similar or like poles. 5.Bring these two recently marked ends together. Describe what happens when two like poles are brought together. 6.Bring one marked end and one unmarked (unlike) end together. Describe what happens when two unlike poles are brought together. Like Poles Repel Attract Unlike Poles 2

Mapping Magnetic Fields          MAGNETMAGNET MAGNETMAGNET MAGNETMAGNET Figure 3 2

Mapping Magnetic Fields 1 2

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Single Magnet Unlike Poles Like Poles

C2 – Matching Magnetic Fields ABCDEABCDE CORRECT Section 1 - Single Magnet N S 2

C2 – Matching Magnetic Fields Section 2 – Unlike Poles N S N S N S N S ABCDEABCDE CORRECT 1

C2 – Matching Magnetic Fields Section 2 – Like Poles N S N S N S ABCDEABCDE CORRECT 0

Viewing Magnetic Fields Using Iron Filings Clear Plastic LidMagnets Iron Filings 1

Viewing Magnetic Fields Using Iron Filings Single 0 Unlike Poles Like Poles 2

The Structure of Magnets RandomAligned Unmagnetized Partially Magnetized Magnetized Iron Figure 6

The Tube and Iron Filing Figure 9

Applying The Magnetic Model To a Iron Wire (Paperclip) Unmagnetized Figure 10 Magnetized Figure 11

Measuring The Strength Of Energy The Inverse Square Law One Distance Unit Two Distance UnitsThree Distance Units Object Strength = 1 Strength = 1 / 4 Strength = 1 / 9 1.Hold the laser 1 meter as indicated in the table and shine on a flat surface. You will notice squares reflecting on the surface. Select one of the squares and draw it on the surface. 2.Hold the laser 2 meters from the surface. Align the same square with one side and bottom. Determine the number of original squares it would take to fill the larger square. 3.Hold the laser 3 meters from the surface. Align the same square with one side and bottom. Determine the number of original squares it would take to fill the larger square. 1/91/41 1/D 2 ∞ intensity 941Distance Squared (D) 941Number of Squares 3-Meters2-Meters1-MeterDistance 12

Floating Magnet 1

The first step is to turn the needle into a magnet. The easiest way to do this is with another magnet -- stroke the magnet along the needle 10 or 20 times. Place your float in the middle of your dish of water. The "float on water" technique is an easy way to create a nearly frictionless bearing. Center your magnetic needle on the float. It very slowly will point toward north. You have created a compass! Creating A Compass 0 Figure 15

The Earth's Magnetic Field N S N S 1 4

0 Magnetic North Pole Earth Geographic South Pole Magnetic South Pole Geographic North Pole

Affect of Electricity on Magnetism Fields 3

Observing Magnetism Associated With Flowing Electrons 2

Investigating the Magnetic Field Associated With Flowing Electrons 1

Describing the Magnetic Field Associated With Current Flowing in a Wire End View Of Wire N S W E Black Red Wire Below Compass N S Black Red Wire Above Compass W E 0 5

Producing and Detecting Electricity Number of Wire Wraps Approx 100Approx 300 Current Detector Movement current detector Coil of Wire Connecting Wire Magnet 8

Hand Generator 7

Motor Generator 6

Flashing Wheels 5

Forever Flashlight 4

Radio Speakers Convert Electrical to Mechanical Energy A speaker takes the electrical signal and translates it into physical vibrations to create sound waves. Speakers do this by rapidly vibrating a flexible diaphragm or cone. The cone is connected to the voice coil. When electricity passes through the coil a magnetic field is produced which interacts with the magnetic field of the magnetic. This causes the coil and cone to move producing sound. 3

Radio Speaker/ Cheepie Speaker 2 Idea from: Al Guenther

Musical Motor 1 Idea from: Al Guenther

Signals Through Space 0 Idea from: Al Guenther

Determining The Strength Of An Electromagnet TrialTurnsObservationIronAluminumWood 125 Compass (Yes or No) Number of Staples 250 Compass (Yes or No) Number of Staples 375 Compass (Yes or No) Number of Staples 4100 Compass (Yes or No) Number of Staples Staples Figure 21

Motors and Generators Figure 7 Magnet Current Armature Commutator Brushes Axle North South Simulation 5

Student Motor Magnet Armature Large Paper Clips Rubber Band 4

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The Finished Motor 0

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