Mathematics/Physics

Magnet Muscles

Objective(s):

Students will be able to recognize the strength of a magnet, what part of the magnet is the strongest, and what is a magnetic attraction.

Materials Needed: (For an entire class)

Several bar magnets and/or magnets of different sizes and shapes, several magnetic objects (paper clips, nails, iron filings, etc.), several nonmagnetic objects (plastic, paper, coins, etc.), pens and/or pencils, data-capture sheet - one per student (pages 13, 15, 23, 72, 82 92), 20 small nails, large nails, 20 metal paper clips, several compasses, a table or flat surface, wooden rulers and construction paper.

Strategy:

1. The teacher will introduce the topic by explaining some basic facts about magnets. Students will be allowed to observe a magnet.
2. The teacher will also explain the concept of a magnetic field. The students will observe the teacher place a bar magnet under a piece of thermal fax paper. A student can be chosen to come up and sprinkle pieces of iron fillings on the paper. Observe to see what will happen. Then teacher can then discuss the magnetic field of a magnet.
3. The teacher will explain the scientific method, which will be used in the lesson.
4. Cooperative Learning Strategies will be explained prior to placing students in cooperative learning groups.
5. Once each group has been placed, the groups will be given the rules for each learning station. Students will have 20 minutes to formulate a hypothesis, test the hypothesis and come up with a conclusion for each station. Predictions and outcomes are to be in written format by the stenographer in each cooperative learning group.
6. Each group begins to research.

STATION A ATTRACTION ACTION

1. Using a bar magnet, select one object at time to see if it is magnetic.
2. Record your findings on the data-capture sheet provided.
3. Once you have tested all of the objects provided, be creative and find five more objects to test for magnet properties.
4. Repeat step 2.

 STATION B MAGNETIC MUSCLE

1. With the 20 nails make a pile on a desk or other hard surface.
2. Choose one magnet and place it in the pile of nails.
3. Slowly lift it out of the pile and record the number of nails it picks up on the data-capture sheet provided.
4. Repeat steps 2-3 with the remaining magnets.
5. Replace the nails with the 20 paper clips and repeat steps 2-4. Compare your results from the first experience.

STATION C MAGNETIC MAP

1. Place the bar magnet in the middle of the piece of paper and trace around it to mark its position.
2. Put the compass on the paper near the magnet. Draw and arrow between the compass and the magnet showing the farthest point where the compass needle is affected by the magnetic field.
3. Repeat step two several times all around the magnet.
4. Once you have completed step three, you will be able to see where the magnetic field exists, where it is the strongest, and where it is the weakest.

STATION D NEIGHBORLY NAIL

1. With the large nail try to pick up some of the smaller nails or paper clips. Observe what happens and record on data capture sheet.
2. With one end of the bar magnet, stroke the nail 25 times in the same direction.
3. Try again to pick up the small nails or paper clips with the newly magnetized nail. Observe what happens and record on data-capture sheet.
4. Carefully throw the magnetized nail against a hard surface.
5. Try one more time to pick up the small nails or paper clips with the nails. Observe what happens and record on data-capture sheet.
6. Repeat this experience using iron fillings instead of nails or paper clip. Observe what happens and record on data-capture sheet.

Performance Assessment:

1. teacher-made test
2. oral- group discussions
3. magnetic journals

References:

1. Boak, Rebecca & Raymond Gabaldon. Magnets. Columbia Education Center's Summer Workshop. May 1994.
2. Bouchier, Alfons. Magnetic Fields and Bermuda Triangles. Los Alamos High School, Los Alamos, NM. 1994.
3. Feigen, Mel.. Magnetism and Electricity. Teacher Created Materials, Huntington Beach , CA., 1994.