Context: Energy usage is an integral part of our modern life as human beings. Everyday, we all use energy in one way or another, however, many of us don’t fully understand where our energy comes from. While there are many different ways energy is produced, in this activity students will create a homopolar motor that produces energy and gain a little more context on how certain aspects of energy work. A homopolar motor is a direct current electric motor which produces constant circular motion because the polarity of the magnetic fields do not change, the direction of the force does not change, and the wire rotates in a constant circular motion.
Goals: Age Group: 4-12
Create a motor using basic household items
Provide a more hands on understanding of electricity
Critically think about how much energy we use
Supplies: Time: 30 mins
Copper wire 14 AWG solid (12-18 AWG is gucci)
First watch the Olympic Cyclist video for context, next follow the procedure for making a motor, then watch the homopolar motor explanation video, finally answer the reflection questions.
https://youtu.be/S4O5voOCqAQ Olympic Cyclist vs Toaster
https://youtu.be/ttD3Jw9OfOI Homopolar Motor explanation
Neodymium magnets are very powerful rare earth metal magnets and they can be dangerous if mishandled. It is our recommendation that you have adult supervision when trying this activity/experiment.
First take your battery and attach the neodymium magnets to the negative side.
After attaching the magnets lay the battery down flat on a sheet of paper and trace ,with your writing utensil , the outline of the battery and and magnets
Next remove the magnets from the battery and place them apart from each other on opposite sides of the table.
Now it’s time to outline where your wire will be. You can make a cool shape if you have enough wire but, for the purpose of functionality we will skip the fancy shapes for now. Feel free to do your own thing at home.
Following the lines that you have on your paper, draw a rough shape of where your wire will be. Start at the bottom where the magnets are; imagine your wire will go up the side of the battery, touch the top of the positive point, and then back down the other side of the battery making sure the wire touches the magnets at the bottom.
Grab your battery/magnets and attach them again like you did before. This time try to assemble the wire in the same fashion as the design on your paper. be sure that the negative and positive points of the battery/magnets are making contact with the wire.
It may take a few times to refine your wire to make sure that it stays upright and touches all of the points. Cut off any excess with your wire cutters (have an adult help you).
Now let it go. If all of the wires points are making contact then, it should start to spin. The spinning motion will gradually increase: so it will start off slow, and perhaps eventually gain enough speed that it will eventually fall off. If this happens then... CONGRATULATIONS, You’ve successfully created a homopolar motor!
Think about all of the things that you use energy for (ovens, lights, heat, video games, etc.). Would you use the same things or do the same things if you had to create the energy needed?
How often do you think about the energy it takes to power the things in our life? Will you think of it more now?
Were you able to successfully create this motor? If not, what do you think was the problem? If yes, can you think of any ways to make it more efficient? Or a different design?
Did you think you could make this motor again without following the instructions?
Do you feel like you have a better understanding of energy, force, or electricity basics?
Did you think Robert would be able to toast the bread completely?
Without any additional tools, do you think you can spin the wire as fast and for as long as the homemade motor you made?
Would you be able to explain how homopolar motors work on your own to a friend?