Title: Using a Compass Which Way Is Which

Title: Using a compass – which way is which? Purpose: How can a compass help you know what?

Part A: Magnetic fields Around every magnet, there is an invisible field called a magnetic field. This field is what attracts items such as paper clips and nails to the magnet. Although it is invisible, we know that we can see the effects of this invisible field in the pattern that is made by iron fillings when we expose them to a magnet. Now let’s explore these fields. As you are working, answer the questions For this activity, you will need the following items:  2 magnets  paper clip  zipper-lock bag with iron filings inside Procedures: 1. Take a zipper-lock bag with iron filings inside and place in on a white paper. 2. Lay the plastic bag on a table and shake it gently back and forth. Let your partner try it, too. With a little practice, you can get a thin layer of filings on top of in your bag. The Filings should not all be in a lump at one end. 3. Can you predict what will happen to the iron filings if you place a magnet on the table and set the bag down on top of the magnet? Write your prediction below:

4. Now place the magnet on the table. Then gently pick up the bag and place it on the magnet. 5. What happens? Do the filings move around? Try it a few times.

6. You can hold the Magnet flat in your hand and set the bag down on it there, too. Draw a picture of the magnetic field you see in your bag below….

Analysis Questions: 1. Why do the filings line up from one end of the magnet to the other?

2. Where is the force of the magnet the strongest? How do you know?

3. What/Where is the biggest magnetic field?

4. How do we know the Earth has a magnetic field? Part B: The earth as a magnet Remember, we cannot really see the magnetic field, but we can see how it moves the iron filings around. This is like the wind outside. We cannot see the wind, but we can see how it moves the leaves on the trees or paper in the street.

1. Do you think the earth is a strong magnet? Explain your thinking

2. Get a class compass – Draw a picture of the class room - where is the front of the room the windows etc. Use the compass and draw what direction is shown on the compass.

3. Why do you think most compasses point the same way?

4. What does this mean about the needle in a compass?

5. To review and practice the directions in your community, complete the following sentences:  My school is _____ of my home.  The closest swimming pool is _____ of where I'm sitting right now.  The closest hamburger joint is called _____ and is _____ of school.  The park is ______of school  Ms Higgins room is ______of our room 6. Magnets have two poles, often referred to as north and south poles. Like poles (N/N or S/S) will repel each other. Opposite poles (N/S) attract each other. What can you infer about the earth and a compass?

Conclusion: observing a phenomenon