Transcript Magnets
Learning Targets Magnets and Electricity Investigation 1 Review INVESTIGATING MAGNETS AND MATERIALS I can identify the kind of materials magnets stick to. • 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. I can explain why magnets may attract or repel each other. 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. I can identify and use objects that will detect magnetic force. • Compasses can be used as detectors because the needle of the compass will always point toward the magnet’s force. • Other good detectors are iron filings, metal screens, and paper clips. I can explain and demonstrate induced (temporary) 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 created by induced magnetism. I can explain and demonstrate the relationship between magnetic force and distance. • 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. Time for a QUIZ! • Which of these items will NOT stick to a magnet? A. Steel nail B. Paper clip C. Aluminum foil D. Penny E. A and B F. C and D F A magnet does not stick to materials that don’t have steel or iron in them, such as a penny or aluminum foil. If two magnets are placed end to end with the same poles touching…. A. The magnets will attract. B. The magnets will repel. B Like poles will repel each other. Which of these items would NOT be a good detector? A. B. C. D. Penny Compass Iron Filings Paper Clip A A penny does not have iron or steel in it, so it could not detect a magnet. Why does the paper clip stick to the nail? A. B. C. D. Force of Repulsion Force of Attraction Magnetic Field Induced Magnetism D Induced magnetism can create temporary magnets from items with steel or iron, as long as the item remains in contact with the magnet. Breaking the Force • What happens to the force of magnetism as the distance between two magnets increases? A. The force gets stronger. B. The force gets weaker. C. Nothing happens to the force. B The force is weaker when there is a greater distance between the magnets. May the “force” be with you.