# 16 April Science 7 Simple machines–assessing our knowledge and then introducing magnets and magnetism– a force leading to a source of energy

1. Assess with probes–partners 4 probes and then individual 2 probes.
2. Also–offer in writing on lined paper (put photo in your digital science notebook) a possible explanation for the spinning toy. How do you think it might work? Use diagrams and good thinking.
3. Show your simple machines homework.
4. See the following pictures–and follow the instructions:

Bar magnets should not touch. They should not be dropped or heated. They should be stored in pairs with opposite poles adjacent to each other with a non-magnetic spacer and “keepers.”

Set up a bar magnet as pictured above. Let it come to rest. What do you notice? How do you think this might work? Magnetism is an example of a force that “acts at a distance.” What could that mean?

What do you notice about the position of the compass needles? This is one way to map the magnetic field around the bar magnet. You and your partner should try this. Record the results. How might this effect be explained? (NOTE: Do not let the compass and magnet touch.)

Examine the pictures above and below. A magnet is placed UNDER the plastic tray. A sheet of paper is placed in the tray so that the iron filings will be easier to see. Try this. Lightly sprinkle iron filings in the tray. Gently tap the tray without moving it with respect to the magnet. Observe the patterns. This is another way to map the magnetic field around a magnet. What ideas come to mind when mapping the magnetic fields? How could magnets work? How do they “act at a distance?” Carefully gather and pour the filing back into the container for the next round. Try different arrangements for the magnets–remember not to let them touch. (NOTE: Do not let the filings come into contact with the magnet.)

What does this patterns suggest about the “shape” and “structure” of the magnetic field around the bar magnet?

What do you see? How do you think the magnets are arranged? Why?

What do you see? How do you think the magnets are arranged? Why?

Which force is stronger–magnetism or gravity? Is this a legitimate question? Why or why not?

What other questions do you have about magnet and magnetism?

## About rfrazier

AES profile = http://aes.ac.in/viewprofile.php?u=6946
This entry was posted in Science 7. Bookmark the permalink.