What is a magnet? For this lesson you can use whatever class materials are required in your state for teaching about magnets. Make sure that you highlight the importance of the North and South poles and the attraction and repulsion between them. Use the video below to teach about how magnetic fields work. (Figure A)
(include VIDEO of magnetic fields)
Hand out a Magnet to each student or pairs of students. Next, ask the students “What do magnets stick to?” and have them look around the classroom, touching the Magnet to objects to test if the Magnet sticks to it. Make sure that US pennies are included in the items that they test. Have them record the items that stick and the ones that don’t in a log in their science notebooks.
Gather the class back together and ask them what they observed. Discuss with them what objects and materials the Magnets stuck to and talk about what metals stick or don’t and why. Use this as an opportunity to introduce the copper Coil (found in the BOSEbuild kit). Ask the students to create a hypothesis about whether the Coil will be attracted to the Magnet. After they discover that the Coil does not stick to the Magnet, have them compare it to other materials they tested; what is it similar to? Discuss how the Coil and pennies are made of the same material, copper, and that it is not attracted to magnets, then list other metals that magnets do or do not stick to and see if they can identify any of the objects that they tested before.
After they have identified objects, hand out the Control Panel and Power Adapter to groups of students (group size depends on oyur class size and your number of BOSEbuild speakers, but try and keep the groups to 2-4 students). Make sure that each group is located near an outlet and instruct them to insert the small end of the adapter into the port labeled “Power” on the lower right corner of the Control Panel. Then instruct them to plug the Power Adapter into the outlet. A white light should appear near the top of the Control Panel.
Now instruct the students to plug the Coil into the appropriate port. Show them that the Yellow Plug connected to the Coil has three circles on it, then tell them to find the port on the Control Panel that also has three circles above it. Make sure that they plug it in all the way, otherwise the experiment will not work.
The students should now be ready to start the experiment. Instruct the students to place the Coil on the Magnet, with the yellow base down.
After making sure that the Yellow Slider on the Control Panel is in the leftmost position, tell the students to press the Yellow Button on the Control Panel one time to change the setting to Red Mode. The Coil will jump off of the Magnet. Encourage the students to place the Coil back on the Magnet and observe what is happening. The Coil will jump off every three seconds, which is just enough time for the students to put it back each time. Explain that the Coil has become an electromagnet. It jumps because an electrical pulse is being sent through from the Control Panel, through the wire, into the Coil. Copper is a material that, when electricity is flowing through it, becomes a magnet. Each time the pulse is sent to the Coil, the copper becomes magnetic, causing it to be repelled away from the Magnet.
Encourage the students to move the Yellow Slider to the right. As they move the slider the Coil jumps less often. Let them experiment with the time variation as the move the Yellow Slider left and right. If the Yellow Slider is in the rightmost position it will jump every 10 seconds.
Moving on from the red mode, have the students push the Yellow Button on the Control Panel so that the cube is in the Yellow Mode and glowing yellow. Make sure that in moving to the yellow mode the slider is pushed to the far left. The yellow mode will cause for the coil to move up and down at different speeds according to the positioning of the slide, getting faster as the slide is moved towards the right. The speed of this motion is called frequency. Frequency is a measurement of “bounces” per second. Have the students trace the motion when the slide is positioned to the far left and then again when it is positioned to the far right. Go through and help them label their wave-like drawings with wavelength, frequency, peak, trough, amplitude, etc. (Figure E).
Explain to the students that wavelength is the number of cycles within a set period of time, peaks are at the highest points of waves, troughs are at the lowest parts of waves, and amplitude is the height of the waves. Ask them questions such as “Which has a shorter wavelength? Which has higher frequency?”
Return back to the Control Panel and have the students watch the motion of the coil, asking them which has a shorter wavelength when switching the positioning of the slide from the far left to the far right (far left has a shorter wavelength). Using what they now know about how magnets and their poles work, have them explain what is happening to the Coil that it is able to move up and down. They should made the connection that the Coil, when receiving electricity, is switch from being the north pole of a magnet (repelling causing it to move upwards away from the magnet) and the south pole of a magnet (attracting causing it to move downwards towards the magnet) which accounts for the up and down motion of the coil on the magnet.
Next Activity: Optimal Height