Magnetic Motion

Welcome to the Magnetic Motion project! In this project, students will explore the interactions of magnets, electricity, and copper wires!

From your teacher, each student will collect 2, 8-inch pieces of wire and each group will need 1, 10-foot piece of wire. Groups will be given magnets, AAA Batteries, and AA Batteries, a button compass, a dowel, and pliers.

A note about safety. The magnets used in this project are high-strength neodymium magnets. This means that they can hurt you if used improperly. So to minimize the chance of any accidents, here are some rules to follow:

1. Do not let the magnets snap together. Sometimes parts of the magnets can chip off. Not only does that damage the magnet, but the chips could injure you! Make sure to bring the magnets together slowly when possible.

2. Don't put the magnet next to any electronics. Modern electronics can be affected by strong magnets. So keep the magnets away from phones, computers, tablets, etc!

3. These experiments are actually short-circuiting the battery. This means that the positive and negative terminals of the battery are hooked together without any sort of load. This can make the wire and the battery very hot. It is best to run the experiments in short bursts (30 seconds MAX) and then have a cool-down period. This also drains the batteries pretty quickly, so that is why your group is given a few batteries to use.

Let's grab our materials and learn about magnets!

In this step, you will learn the basics of magnets and magnetism.

Using the materials we have How can we identify the north and south poles of our magnets?

Now that we have learned about some magnetic properties, let's use these magnets in a simple circuit!

In this step, you will create a basic homopolar motor.

But first, we need to learn a little about current. When you touch a wire to the positive and negative leads of the battery, a circuit is created.

What happens when you touch one of your 8-inch wires to the positive and negative ends of a battery near your compass? Does anything happen?

 

 

 

 

 

 

 

 

 

 

 

 

Any time an electric current is present, a magnetic field is created! Then, when this electric field is created in an existing magnetic field (caused by the magnets on the bottom of the battery), then a force is created!

Watch the first two minutes of this video:

 

After watching the video, take two or three of your magnets, one of your 8-inch pieces of wire, and one AA battery, and try to make your own homopolar motor!

If you finish early, try to tweak your wire to make your homopolar motor go as fast as possible!

Once you have experimented with your homopolar motors, we will move on to make a tiny dancer!

In this step, you will create a second homopolar motor in the form of a tiny dancer!

In the last step, you created a balanced homopolar motor. Now, can you make a second one with one of the legs bent up into the shape of a tiny dancer? 

How was this different from the first homopolar motor? Was this more or less difficult to do?

Now that we have explored homopolar motors, we are going to look at magnetic trains!

In this step, you will use a non-uniform electric field to create an electric train!

After watching the video, take the dowel and the 10-foot piece of wire and wind it. You want to wind it as tight as you can (see the picture,  right). This hammer's handle is a nice 5/8" dowel like you have. If you're working in a group, take turns winding the coil as it can be a tough process.

After you wind your coil, slide it off the end of the dowel. You should have a coil that is 4 or 5 inches long.

Now, assemble your "train." You will need 1 AAA battery and at least 2 magnets. Try putting your train in the coil. What happens?

Now, evenly stretch the coil so that it is about 9 inches long. Make sure the coils are fairly evenly spaced.

Experiment with the orientation and number of magnets until your train moves through the coil. What orientation worked best for the batteries and magnets (discuss in terms of the positive and negative sides of the battery and the north/south poles of the magnets)?

Later in the video, Physics Girl uses multiple batteries in a single "train." Can you make a train comprised of multiple batteries?

Using an Online Stopwatch, time your train as it goes through your coil. Create a table like this on paper. Add rows as needed.

Number of Batteries	Number of Magnets in the front	Number of Magnets in the back	Number of batteries in the middle	Time it took to pass through coil

After you have run some trials, do you have enough data to answer these questions?

--How does the number of batteries affect the time it takes to go through the coil?

--How does the number of magnets in the front affect the time it takes to go through the coil?

--How does the number of magnets in the back affect the time it takes to go through the coil?

--How does the number of magnets in the middle affect the time it takes to go through the coil?

 

Can you work with other groups to try to loop a train through multiple coils? 

In this step, you will reflect on the Magnetic Motion project. 

1. What parts of this project were easy? Which parts were more difficult?

2. Did you run into any problems while constructing your homopolar motor, Tiny Dancer, or electric train? Were you able to find a solution on your own? If not, where did you find help with a solution?

3. What did you learn about magnets?

4. What did you learn about motors?

5. From your experiments with the homopolar motor/Tiny Dancer, what made for the best motor/dancer?

6. From your experiment with the train and magnets, which combination (positive/negative battery terminals and North/South poles) allowed your train to move through the coil?

7. From your testing with the electric train, what combination of batteries and magnets made the fastest time going through the coil? Why do you think that was the case?

8. As a result of this project, please share one new idea or new question you may have come up with or encountered.

In this optional extension, you will create a DC motor and will change characteristics to try to get the motor to spin the fastest.

Start by watching this short video from the Bearded Science Guy.

Next, get your materials. For your first motor, use approximately 12 inches of magnet wire. Follow the instructions in the video except use magnets to hold the paper clips on the end. I also made the paper into a stand that held the motor over to the side of the battery. 

Once you have a working motor, how can you make it go faster? Could you increase the number of coils? What about the thickness of the magnet wire (your teacher may or may not have other magnet wires)? What about the number of magnets and the distance between the coil and the magnet(s)? Could you increase the voltage by adding more magnets?

Since the motors are spinning very quickly, how can we count the number of turns every second (RPS) or minute (RPM)?

After trying out a few different combinations, what factors did you find helped make your motor run faster?