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Lesson 6: Magnetism. Objectives: 1. Recognise that magnetic forces act on magnetic materials 2. R ecognise magnetism as a force at a distance. Navigation with magnets.
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Lesson 6: Magnetism Objectives: 1. Recognisethat magnetic forces act on magnetic materials 2. Recognisemagnetism as a force at a distance
Navigation with magnets Place a bar magnet on the + mark on the map below. Hold your second magnet by the string and move it over each of the ships in turn. What happens to the magnet?
9.4 Field lines How do compasseswork?
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.
Using Magnets • Try to pick up other metals now. Why or why can’t you pick them up? Create a table to organise your results. • Place the magnet under a piece of white paper. Gently pour the iron fillings around (not on) the magnet. What shape do you see? Draw the shape in your notebook.
9.4 Magnetic fields MagneticFields
Permanent vs Temporary magnets • Rub the magnets with the nail • Then pick up the pins with the nail. • Record in your table how many pins could you pick up and for how long. • Explain your observations
What are magnetic domains? - Substances like iron, cobalt, and nickel are composed of regions called domains. - These domains align themselves in the same direction (N/S) when placed in a magnetic field. - This allows the substance to be magnetic for awhile.
Magnet Summary 1. There are North Poles and South Poles. 2. Like poles repel, unlike poles attract. 3. Magnetic forces attract only magnetic materials. 4. Magnetic forces act at a distance. 5. While magnetized, temporary magnets act like permanent magnets HOMEWORK: Bring copper, an iron nail and 9V battery for next class