0.20 kg ballwarm up 10 the ball (0.20 kg) in the diagram is moving at a speed of 12 m/s. what is the...
TRANSCRIPT
0.20 kg ball Warm Up 10
• The ball (0.20 kg) in the diagram is moving at a speed of 12 m/s. What is the momentum of the ball in kg · m/s? Record and bubble in your answer to the tenths place on the answer document.
• Magnets are essential parts of today’s world– Electricity would be rare– No hard drives– No MRI (Magnetic Resonance Imaging)
machines
• Lodestones are naturally magnetic rocks
• Magnetism was considered the 5th fundamental force of nature– Gravity
– Electricity
– Magnetism
– Strong Nuclear
– Weak Nuclear
• Hans Christian Oersted (1820) discovered that Electricity and Magnetism were the same force– You can create a magnet with electricity– You can create electricity with a magnet
• Magnets are made of special alloys of metals
• Magnets always have a North and South Pole– Break a magnet and you still get both poles
• Similar to charges and masses, magnets produce a force field, a magnetic field.
• A magnetic field is created when a charge moves
• What is moving to create the magnetic field of a magnet?
• Electrons orbit the nucleus AND spin on an axis
• Their motion creates a magnetic field
• Which do you think is more important to magnetism, electrons orbiting the nucleus or the electrons spinning on an axis? Why?
• Electron spin because the electron orbit is very random
• Since all atoms have electrons that move, why isn’t everything magnetic?
• Destructive Interference cancels out most of the magnetic forces
• Magnetic fields of individuals atoms can polarize nearby atoms
• These create Magnetic Domains inside an object
• The better aligned, the more powerful the magnet
• Magnets can induce temporary magnets
• Permanent magnets:– Rub a magnet over a piece of iron– Place a piece of iron in a strong magnetic field– Place a piece of iron near a strong
electromagnet
• What do all three ways have in common? (Think back to magnetic domains)
• They all try to align the magnetic domains of a piece of iron
Exit Ticket 1
• Which way would a compass point if you were 100 m in the air, above the North Pole?