Introduction: (Initial Observation)
With advances in production of very strong magnets and electromagnets, now we can use magnets and electromagnets in many new products. Some of such products use the repelling magnets to create floating objects including the magnetic levitating trains. Levitating trains with magnets or electromagnets can greatly reduce the friction, sound and can increase the speed while giving a smooth ride. In some other instruments repelling magnets are used to create a spring like force.
In this project you will experiment the repelling force of magnets.
Information Gathering:
Find out about magnets and electromagnets. Read books, magazines or ask professionals who might know in order to learn about uses of magnets in different devices or equipments. Keep track of where you got your information from.
Following are samples of information you may find:
History of Permanent Magnets
Lodestones
The history of permanent magnets goes back to ancient times. Records from early Greek, Roman and Chinese civilizations make reference to rare and mysterious stones called lodestones. These lodestones could attract each other and also small pieces of iron in what seemed a magical way and when suspended from a thread, they always pointed in the same direction. We now know that lodestones contain magnetite, an oxide of iron and that they are a naturally occurring magnet having the composition Fe3O4.
Although lodestones were considered an intriguing phenomenon by scientists of the day, they were not really utilized in any constructive way until around 1200 AD with the introduction of the mariners (magnetic) compass. The mariners compass is a device housing a pivoting magnetized needle, which freely and consistently points towards magnetic north. This enables travelers to consistently and safely navigate their way from one place to another.
Source: http://www.lodestoneindustries.com.au/aboutmagnets.asp
Here is a paper describing “Methods of Magnetizing Permanent Magnets” by Joseph Stupak, Jr.
How are magnets made?
There are 6 basic steps to making a magnet, such as a Neodymium Iron Boron magnet = Nd2Fe14B or Nd15Fe77B8.
1. Make an alloy of iron, boron and neodymium. You will need about 0.014 pounds of boron and 0.369 pounds of neodymium for every pound of iron to make an alloy of Nd2Fe14B. This will have to be heated above 1538 degrees Centigrade to make it melt. The mixing of the materials with the iron is very important, just like thoroughly mixing the ingredients for a cake.
2. Grind the alloy into a powder. After the alloy has cooled, you will need to grind it or mill it into a very fine powder.
3. Compress the powder into a shape. Since the magnet will have a specific shape when you are done, you use a mold of that shape to make the magnet. For example, you may want a disk. Pour the powder into a mold that has a disk shape, but is also deeper than the thickness of the final part. Next, you will compress the powder with hundreds of pounds of pressure to compact the powder into a solid disk. Heat is often used to help fuse the particles together, and is called a sintered magnet. Sometimes a glue is used to help keep it all together, and is considered to be a bonded magnet. To achieve precise final dimensions, you may need to grind the part.
4. Coat the magnet. In order to improve the corrosion resistance of the magnet, the disk needs to be plated with a thin film of nickel. Sometimes a film of gold is used, or zinc, or an epoxy coating.. Nickel does not oxidize like iron, so it works great for magnets you will be touching.
5. Magnetize the magnet. All this time, the powder and the disk is not magnetized. It would be attracted to and stick to a magnet, but it would not be able to pick up a paper clip all by itself. So, it would be placed into a magnetizing fixture that has a coil of wire through which a very large pulse of current is passed for a very short period of time. The magnet has to be held in place so it doesn’t shoot out and hit something or someone. It takes about a thousandth of a second to actually magnetize the magnet.
6. Pack and ship it. You now have a magnet for whatever you need. Engineers often require special shapes or specific magnetization configurations to make the product they are designing work properly. They talk with the magnet manufacturer and they determine how to best make the magnet that is needed. That’s why there are so many different shapes and sizes of magnets in the catalogs.
Question/ Purpose:
What do you want to find out? Write a statement that describes what you want to do. Use your observations and questions to write the statement.
Question 1: How does the distance between ring magnets change as you stack them so that they repel each other?
Question 2: Is the distance of floating magnet rings affected by their position in the stack?
Question 3: How does the distance between magnets change if at the base of the stack you place 2 or 3 attracting magnets?
Identify Variables:
When you think you know what variables may be involved, think about ways to change one at a time. If you change more than one at a time, you will not know what variable is causing your observation. Sometimes variables are linked and work together to cause something. At first, try to choose variables that you think act independently of each other.
This is how you may define variables for Question 1:
The Independent variable is the amount of load or weight on repelling magnets.
The dependent variable is the distance between the repelling magnets.
Hypothesis:
Based on your gathered information, make an educated guess about what types of things affect the system you are working with. Identifying variables is necessary before you can make a hypothesis.
Sample hypothesis for question 1:
I hypothesize that the distance between the repelling magnets will reduce by increasing pressure. I also hypothesize that the repelling force will increase as the magnets get closer to each other. My hypothesis is based on the fact that each additional magnet added to the stack will cause some downward force to all repelling magnets bellow itself.
Your hypothesis for question 2:
Try to write your own hypothesis for this question. Your prediction is your hypothesis. For example you may predict that stacked magnets will stay equidistance from each other. In other words all magnets will have the same distance to the magnets below or above them. Or you may predict that the distance between magnets will increase (or decrease) as we move up in the stack.
Write down your hypothesis and your reason for that before you do your experiment. Your experiment will be stacking the ring magnets in an arrangement that they repel each other.
Experiment Design:
Design an experiment to test each hypothesis. Make a step-by-step list of what you will do to answer each question. This list is called an experimental procedure. For an experiment to give answers you can trust, it must have a “control.” A control is an additional experimental trial or run. It is a separate experiment, done exactly like the others. The only difference is that no experimental variables are changed. A control is a neutral “reference point” for comparison that allows you to see what changing a variable does by comparing it to not changing anything. Dependable controls are sometimes very hard to develop. They can be the hardest part of a project. Without a control you cannot be sure that changing the variable causes your observations. A series of experiments that includes a control is called a “controlled experiment.”
Experiment 1:
Floating ring magnets are among the experiments and demonstrations you may perform with the ring magnets. In this project you use the vertical wood dowel or pencil to stack a group of ring magnets and tray to predict their distances.
Question/ Problem:
How does the distance between ring magnets change as you stack them so that they repel each other?
Materials:
- 6 ceramic ring magnets
- A wood dowel (may be replaced by a pencil)
Preparation:
Mount the wooden dowel or a pencil on a flat wooden board using wood glue or by making a same size hole on the board.
Sanding the wood dowels may be required:
The wood dowel or pencil must easily slide trough the hole in the center of ring magnet. If this does not happen, please use a sand paper to sand the wood dowel. Sanding will reduce the diameter and smoothen the surface.
Procedure:
- Drop the first ring magnet onto the wood dowel.
- Drop the second magnet onto the wood dowel so that it will repel the first ring magnet. If they don’t repel each other, take out the second magnet, turn it over and drop it again onto the dowel.
- Measure the distance between the two magnets and record it in your data table.
- Drop the third magnet onto the wood dowel so that it will repel the second ring magnet. If they don’t repel each other, take out the third magnet, turn it over and drop it again onto the dowel.
- Measure the distance between the first two magnets and record it in your data table.
- Add the fourth, the fifth and possibly the sixth magnet so that all magnets repel each other and by adding each magnet, repeat measuring and recording the distance between the first two magnets.
- Record your observations in a table like this:
| Number of rings in the stack | Load = Number of repelling magnets above the first two | Distance of the first two magnets |
| 2 | 0 | |
| 3 | 1 | |
| 4 | 2 | |
| 5 | 3 | |
Make a graph:
You may use a bar graph to visually present your results. Make one vertical bar for each amount of load. The height of each bar will show the distance of the first two magnets. (The height of bars may be increased by about 5 to 10 times for better visibility).
Experiment 2:
Magnetic field of magnets on a stack of repelling magnets may extend to affect many magnets on that stack. In this experiment we examine the distance between all magnets in the stack of 5 or 6 ring magnets.
Question/ Problem: Is the distance of floating magnet rings affected by their position in the stack?
Procedure:
- Insert all 5 or 6 magnets onto the dowel in a way that each magnet repels the magnets bellow and above itself.
- Measure and record the distance between the magnets.
- Your data table may look like this:
| Order in the stack from the bottom | Distance to the magnet bellow |
| 2 | |
| 3 | |
| 4 | |
| 5 | |
No graph is required:
Make a drawing or take a picture of the stack to show the relative distance between the magnets in different positions of the stack.
Experiment 3:
When more than one magnet are bundled together, they will have a magnetic force that is different from each single magnet. In this experiment we will examine the change in the repelling force of bundled magnets.
Question/ Problem: How does the distance between repelling magnets change if at the base of the stack you place 2 or 3 attracting magnets?
Procedure:
- Place a single magnet onto the wood dowel and add a second magnet in a way that it repels the first magnet.
- Measure and record the distance of the two magnets.
- Repeat the steps 1 and 2 by placing 2 and 3 bundled magnets (attracting magnets) at the bottom.
- Record your results in a table like this:
| Number of bundled magnets at the bottom | Distance of the top repelling magnet |
| 1 | |
| 2 | |
| 3 |
Make a graph:
You may use a bar graph to visually present your results. Make one vertical bar for each number of magnets in the bundle. The height of each bar will show the distance of the top (repelling) magnet. (The height of bars may be increased by about 5 to 10 times for better visibility).
Magnetic Equilibrium Demonstration
The downward force of gravity may balance with an upward repelling force of a magnet to form an equilibrium. A magnetic equilibrium may also involve more than one magnet.
Finding the equilibrium is a challenging task. It becomes more challenging if the equilibrium is involving more than one element. Elements in an equilibrium are sensitive to small forces that may change the balance of the equilibrium.
Try this:
In this experiment you use the rectangular magnets that you received with your kit. You need a rough surface so the magnets can not slide on that. You may use a sand paper as the ground for these experiments.
Identify the poles: Move one face of the magnet towards the compass (from the side). The compass will show if that face is North or South. Mark both faces in all your rectangular magnets.
Find the equilibrium: Place one magnet horizontally and then move another magnet towards that from the top such that like poles are facing each other and two magnets repel. When you feel the repelling force, gradually and slowly move the upper magnet to one side and let it stand in one edge. Adjust the distance to find the equilibrium. If your flat magnet starts to move, temporarily hold it with your finger or put some sticky material under that so it will not move.
Additional magnets can be added to this equilibrium from the side. Again like poles must face each other.
Find out how many slanted magnets you can stand in row in an equilibrium state.
If you don’t have a rough surface for this experiment, you may need to use tape to hold the bottom of the magnets in place.
The equilibrium may be achieved with different arrangements of different magnets.
Make a Magnetic Levitating Train
Introduction: In magnets like poles repel. In other words N poles repel N poles and S poles repel S poles. The abilities of magnets to repel each other has provided the idea of making levitating trains. Levitating trains do not make a loud noise as regular trains do. They can also travel faster due to lower friction between the train and the rails.
Magnetic trains do not need wheels. They just need a magnetic rail on the ground and a like magnetic rail on the train cars.
Materials
To construct a model of magnetic levitating train you will need the following materials.
Included in your kit:
- 2 long hi-force Magnetic Strips (for the rails)
- 2 short hi-force Magnetic Strips (for the car)
- 2 plastic Guide Rails
- Wood Block 5″ x 1 1/2″ x 3/4″ for the car
Additional materials you need:
- Wood board or heavy cardboard 3″ x 28″ or larger. This will be the ground for your train.
- Clear adhesive tape
- Foam board or construction paper for making a decorative train
- Wood glue or Elmer glue to connect the foam parts (optional)
- A ruler stick
- Pencil
- This instruction page
Procedure Quick Reference:
- Peal the plastic film from the back of 5″ long magnet strips and connect them on one side of the 5″ x 1 1/2″ wood block. This will be the train car. As you see in the picture in the right, the strips are aligned to the edges of the wood block and are 1/2″ apart.
- Peal the plastic film from the back of 24″ long magnetic strips and mount them parallel to each other, exactly 1/2″ apart, on a long wooden board or rigid card board.
- Mount the clear plastic angles on the sides of the long magnetic strips to form a protective wall so the levitating car will not move off rail. There must be a very small gap between the car and the walls so the car can move freely.
In this method the angle brackets are installed towards outside. In other words the horizontal surface of the brackets are away from the rails. This methods allows you to adjust the position of side rails later. The angle brackets can be secured using masking tape, clear adhesive tape, or small screws.
Another method described in the detail procedure below is suggesting the brackets to be mounted towards inside. You choose which method you want to use.
Procedure Details:
- Draw 2 parallel lines 24″ long and 1/4″ apart as the guideline for mounting plastic rails (angle brackets). Number these lines as line 1 and line 2.
- draw 2 more parallel lines 1/8″ outside the first two lines. These 2 new lines will be used as the guideline for the magnet strips. We name these new lines , line A and line B.
- Place one of the angle brackets on the board and align its edge to the line number 1. At this time the flat section of the angle bracket will cover the line A and the wall section of that will stay on the left of line A. Use tape to secure it at this position.
- Place the other plastic angle bracket on the board and align its edge to the line number 2. At this time the flat section of the angle bracket will cover the line B and the wall section of that will stay on the right of line B. Use tape to secure it at that position.
5. Place your train car between the rails and make sure that it can move freely and the space between the walls and train is as small as possible.
6. Peal the plastic film from the back of 24″ long magnetic strips and mount them on the flat section of angle brackets. One must be aligned to line A and the other must be aligned to line B. In this way two magnetic strips will be exactly 1/2″ apart.
7. Place the rail board on a flat horizontal surface and then place the train car over the rail. It must float and the side brackets must protect it so it does not go off road.
Further adjustments and alignments:
If the magnets are very strong you may need to make your train heavier by adding weights or loads. You may also use the super strong neodymium magnet to modify the strength of your plastic magnet strips. Please be cautious in doing this because imbalance in the strength of magnet strips can potentially disable your train.
To increase the strength of plastic magnet, place the neodymium magnet on the magnet strip so that it will be attracted, then rub the magnet all over the surface of both rails on the ground.
To reduce the strength of magnet, hover the neodymium magnet above the magnet strip so that it will be repelled by the plastic magnet, then move it along the rail.
To be more precise in this procedure, you must first identify the N and S of your plastic magnets and your neodymium magnet. You may use a compass to identify the poles. The south pole of the compass needle is the one that shows the north and attracts to the N pole of magnets. Also the North pole of a compass needle stays towards the south pole and attracts toward the S pole of magnets.
To increase the strength of plastic magnet, rub its surface with the opposite pole of the neodymium magnet. To reduce its strength, hover the like pole of the neodymium magnet above its surface.
Note: Super strong Neodymium magnet is also able to reverse the poles of a plastic magnet. For example if the surface of plastic magnet is N, you can rub that surface with the N pole of neo magnet in order to change it to S.
Decoration:
Make a decorative train using Styrofoam or construction paper and mount it over your wooden train base. A decorative structure makes your train more attractive for your science project display.
You can glue or tape any decorative train car above your wooden train.
If you cut the foam to exact size of your wooden train, you will not need to use tape or glue. The model can sit right on the top of the wooden train and hold it snugly.
Additional upgrades:
The wooden train or the decorative train above that may be equipped with ejecting magnets so they can smoothly eject at the end of the rail.
Ejecting magnets are usually rectangle magnets or small disk magnets that may be screwed or taped to both ends of a train.
To make these work, matching magnets must be mounted at the end of each rail in a way that they repel the train magnets.
The magnets at the end of the rail must be fully aligned with the train magnets so they can repel the train when it gets to the end of line.
End of line magnets may be mounted on another wood block or a small cardboard or plastic box.
Picture in the right shows an end of line magnet mounted on a wooden block that is hold in place using rubber bands.
Materials and Equipment:
Materials used in this project include:
- 20 Ceramic Magnets
- Super-strong NEODYMIUM Magnet
- Hi-force Magnetic Strips
- Plastic Guide Rails
- Compass
- Iron Filings
- Wood Block
- Wooden dowel
- Online instructions
The above materials are available in the KITML from MiniScience. You can click on the above picture to order them.
Additional materials you need:
- Wood board or heavy cardboard 3″ x 28″ or larger. This will be the ground for your train.
- Adhesive tape
- Wood glue or Elmer glue to connect the foam parts
- Nails with diameter less than the hole on the sheaves (Wheels)
Results of Experiment (Observation):
Experiments are often done in series. A series of experiments can be done by changing one variable a different amount each time. A series of experiments is made up of separate experimental “runs.” During each run you make a measurement of how much the variable affected the system under study. For each run, a different amount of change in the variable is used. This produces a different amount of response in the system. You measure this response, or record data, in a table for this purpose. This is considered “raw data” since it has not been processed or interpreted yet. When raw data gets processed mathematically, for example, it becomes results.
Calculations:
If you do any calculations, write your calculations in this section of your report.
Summary of Results:
Summarize what happened. This can be in the form of a table of processed numerical data, or graphs. It could also be a written statement of what occurred during experiments.
It is from calculations using recorded data that tables and graphs are made. Studying tables and graphs, we can see trends that tell us how different variables cause our observations. Based on these trends, we can draw conclusions about the system under study. These conclusions help us confirm or deny our original hypothesis. Often, mathematical equations can be made from graphs. These equations allow us to predict how a change will affect the system without the need to do additional experiments. Advanced levels of experimental science rely heavily on graphical and mathematical analysis of data. At this level, science becomes even more interesting and powerful.
Conclusion:
Using the trends in your experimental data and your experimental observations, try to answer your original questions. Is your hypothesis correct? Now is the time to pull together what happened, and assess the experiments you did.
Related Questions & Answers:
What you have learned may allow you to answer other questions. Many questions are related. Several new questions may have occurred to you while doing experiments. You may now be able to understand or verify things that you discovered when gathering information for the project. Questions lead to more questions, which lead to additional hypothesis that need to be tested.
Possible Errors:
If you did not observe anything different than what happened with your control, the variable you changed may not affect the system you are investigating. If you did not observe a consistent, reproducible trend in your series of experimental runs there may be experimental errors affecting your results. The first thing to check is how you are making your measurements. Is the measurement method questionable or unreliable? Maybe you are reading a scale incorrectly, or maybe the measuring instrument is working erratically.
If you determine that experimental errors are influencing your results, carefully rethink the design of your experiments. Review each step of the procedure to find sources of potential errors. If possible, have a scientist review the procedure with you. Sometimes the designer of an experiment can miss the obvious.
References:
List of References in this section of your report. The list of your references is also known as bibliography. This may include the online or printed references.
