A magnetic levitation demonstration shows how magnetic forces can lift a small object without direct contact. In this project, a lightweight foam train hovers above a track made from neodymium magnets arranged so that like poles face each other. The visible gap between the train and track makes magnetic force easier to observe, measure, and connect to real maglev transportation systems.
It is a strong classroom project because students can build it, test variables, and improve the design using evidence.
Key Facts
- Like magnetic poles repel and unlike magnetic poles attract.
- Magnetic force increases as the distance between magnets decreases.
- A stable maglev track needs lift force upward and side guidance to reduce tipping or sliding.
- If the train is at rest while levitating, the upward magnetic force is approximately equal to the weight: Fmag = mg.
- Weight depends on mass and gravity: W = mg, where g = 9.8 m/s^2 near Earth.
- Changing magnet orientation changes the field pattern, which can change both gap distance and stability.
Vocabulary
- Magnetic levitation
- Magnetic levitation is the lifting of an object using magnetic forces instead of direct physical support.
- Neodymium magnet
- A neodymium magnet is a strong permanent magnet made from neodymium, iron, and boron.
- Magnetic field
- A magnetic field is the region around a magnet where magnetic forces can act on other magnets or magnetic materials.
- Repulsion
- Repulsion is the pushing force between like magnetic poles, such as north facing north or south facing south.
- Equilibrium
- Equilibrium is the condition in which forces balance so an object does not accelerate.
Common Mistakes to Avoid
- Putting magnets in mixed orientations, which is wrong because alternating north and south poles can create attraction instead of the intended repelling lift.
- Using a foam train that is too heavy, which is wrong because the magnetic force may not be large enough to balance the train's weight.
- Measuring the gap from different reference points, which is wrong because inconsistent measurements make trials impossible to compare fairly.
- Ignoring sideways stability, which is wrong because a train can lift vertically but still flip, slide, or snap sideways off the track.
Practice Questions
- 1 A foam train has a mass of 0.045 kg. What upward magnetic force is needed to levitate it at rest? Use g = 9.8 m/s^2.
- 2 In three trials, a train levitates with gap distances of 4.0 mm, 5.5 mm, and 6.5 mm after the number of track magnets is increased each time. What is the average gap distance?
- 3 Two maglev designs lift the train to the same height. One has magnets only under the center of the train, while the other has magnets under the center plus side guide magnets. Explain which design is likely to be more stable and why.