Warm-up (Week 8) 3/1/12 1. Which 2 forces operate to keep a moon in orbit around a planet? Inertia and gravity Inertia and friction Friction and gravity Distance and gravity

Warm-up (Week 8) 3/1/12 2. Which is a chemical property of matter? Density Magnetism Combustibility color

Warm-up (Week 8) 3/1/12 3. You need to measure the mass of a quantity of sugar for use in an experiment. Which tool should you use? Triple-beam balance Graduated cylinder Ruler Spring scale

Warm-Up Activity Work with your shoulder partner to complete the assignment. You will have about 10 minutes to complete this mini-lab.

Magnetic Attraction Mini-Lab (pg Magnetic Attraction Mini-Lab (pg. 509) Copy the following chart in your INB (pg. 49) Objects # of Paper Clips Observations 1. Unmagnetized Iron Nail 2. Magnet or Magnetite 3. Magnet against Nail Head 4. Nail with Magnet Removed 5. Magnetized Nail Complete the Analysis Questions in COMPLETE SENTENCES when finished with experiment.

How do magnets exert force on each other? Essential Question How do magnets exert force on each other?

What makes an object a magnet?

A magnet is an object that is surrounded by a magnetic field and that has the property of attracting iron.

Properties of a Magnet Two Poles - the area of a magnet where the magnetic effect is the strongest; every magnet has two poles – often called north and south

Properties of a Magnet Magnetic Force - attracting (pulling) or repelling (pushing) other magnets and some other materials (e.g. iron and steel); caused by moving or spinning electric charges

Properties of a Magnet

Properties of a Magnet Magnetic Field - area around the magnet in which magnetic forces act; concentrated into a pattern of lines that extend from the magnet’s north pole to its south pole.

Properties of a Magnet

What is a magnetic field? VIDEO http://www.neok12.com/php/watch.php?v=zX4752067171765e67545d45&t=Magnetism

Properties of a Magnet Magnetic energy results when an object is moved a distance by a magnetic force.

Properties of a Magnet Two Kinds of magnets Temporary - easy to magnetize and demagnetize easily Permanent - hard to demagnetize

How is a magnet made?

For an object to be magnetic, most of its domains (tiny magnetic fields produced by spinning electrons) must line up in the same direction.

Magnetism Magnetism Brainpop

Losing Magnetic Alignment by: a) Dropping a magnet or hitting it too hard b) Putting magnet in opposite field for too long c) Increasing the temperature

What do you think would happen if you cut a magnet in half?

If you cut a magnet in pieces, each piece will still be a magnet with two poles.

Why does a compass point to the Earth's North Pole?

Why does a compass point to the Earth's North Pole? A compass points to the Earth’s North Pole because the Earth acts like a giant magnet. Earth has a north magnetic pole and a south magnetic pole. Earth’s magnetic poles are not exactly the same locations as the geographic poles (axis where the Earth spins).

Why does a compass point to the Earth's North Pole? A compass needle points north because the magnetic pole of Earth that is closest to the geographic North Pole is a magnetic south pole. A compass needle points to the north because its north pole is attracted to a very large magnetic south pole.

EARTH AS A MAGNET

Earth’s magnetic field plays a part in making auroras Earth’s magnetic field plays a part in making auroras. An aurora is formed when charged particles from the sun hit oxygen and nitrogen atoms in the air. The atoms become excited and then give off light of many colors.

Earth’s magnetic field blocks most of the charged particles from the sun. But the field bends inward at the magnetic poles. As a result, the charged particles can crash into the atmosphere at and near the poles. Auroras seen near Earth’s North Pole are called the northern lights, or aurora borealis (aw RAWR uh BAWR ee AL is). Auroras seen near the South Pole are called the southern lights, or aurora australis (aw RAWR uh aw STRAY lis).