Presentation on theme: "By Mosharraf Hossain Tamara Shorter John Heyenga"— Presentation transcript:
1By Mosharraf Hossain Tamara Shorter John Heyenga Magnetic InteractionByMosharraf HossainTamara ShorterJohn HeyengaEd / Summer ’08
2Which items a magnet will attract? Test the items listed below and record your answers in your Book. Next slide will reveal answers.ButtonYarnNuts & BoltsScissorsMarblePennyPaper ClipPencilNoYesItem
3What will make a magnet move? ButtonYarnNuts & BoltsScissorsMarblePennyPaper ClipPencilNoYesItem
4Will these items be attracted to a magnet? yesyesyesNoNONOyesnoyesnoyesno
5The power of magnetic interaction. wow!The power of magnetic interaction.
6Were you correct? Why were these things attracted to the magnet?
7What will happen when the ends of the two bar magnets are placed close together?
8The North and South poles of the magnet are attracted to one another. Like poles of the magnet are not attracted, or repel one another.NSSN
9What is magnetism?Magnetism is the force of attraction between magnets and magnetic objects.
10Graphic Organizer (K W L H Chart) What We KnowWhat We Want to LearnWhat We LearnedHow 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.
11Magnetic 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.
13ElectromagnetA 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.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.
15What 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.
18Magnetic Forces Scavenger Hunt 1) Write three questions for the class from this video.Experimenting With magnets.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.A game about magnetic forces.Write two questions for the class about what you observed.Hunt for Magnetism: A treasure hunt on magnetismThe scavenger sites as well as the treasure hunt site is located on the filamentality website.
19Additional Online Resources Magnet SongHow does electricity create a magnet?CartoonsMutual Distraction (Cartoon)Underdog CartoonMagnet QuizTeaching magnets to students
20Can 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.
21The earth is like a giant magnet! The nickel iron core of the earth gives the earth a magnetic field much like a bar magnet.
22North poles point north, south poles point south. Like poles repel, unlike poles attract.A coil of wire with an electric current flowing through it becomes a magnet.A charged particle experiences no magnetic force when moving parallelWhile magnetized, temporary magnets act like permanent magnets.Putting iron inside a current-carrying coil increases the strength of magnetA changing magnetic field induces an electric current in a conductor.Magnetic forces attract only magnetic materials.Magnetic forces attract only magnetic materials.Magnetic forces act at a distance.
23What are magnets used for? & Why do we need to learn about them?
24Do 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.
25Computers use magnets on all of these parts: Cooling fansFloppy disk spinnerCD spinnerDVD spinnerHard disk spinnerNever put a magnet near acomputer or it will cause the magnetsinside the computer to mess up.
26Magnets 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.
27What else are magnets used for? The RefrigeratorUses 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
28What 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.
29Without magnets, you would not be able to…. Use the microwaveHave a dishwasherHave a furnaceUse a credit cardHear the phone ringOr hear the door bell ringAll of these things use magnets to work!
30Cont. Without magnets, you would not be able to…. Post up your sports schedules on the refrigeratorTurn on the ceiling fanUse the electrical can openerRide in a moving cars(that’s right, cars have LOTS ofmagnets inside to make them work!)
31Magnets are all around us 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.