A magnetic levitation train project shows how magnets can lift and guide a small model train without wheels touching the track. In a classroom version, ring magnets under a light car line up with matching ring magnets on a paper track over a foam base. When like poles face each other, the magnets repel and create an upward force.
This makes the car hover slightly, which reduces friction and makes the motion look futuristic.
Key Facts
- Like magnetic poles repel: north repels north and south repels south.
- Opposite magnetic poles attract: north attracts south.
- For the train to levitate, upward magnetic force must be about equal to the car's weight.
- Weight is calculated by W = mg, where m is mass and g is about 9.8 m/s^2.
- Friction is smaller when the car is not rubbing against the track.
- More magnet pairs can spread the lift force and help the car hover more evenly.
Vocabulary
- Magnetic levitation
- Magnetic levitation is the lifting of an object using magnetic forces instead of physical supports.
- Repulsion
- Repulsion is a force that pushes objects away from each other, such as two like magnetic poles.
- Magnetic pole
- A magnetic pole is one end of a magnet, labeled north or south, where magnetic effects are strongest.
- Friction
- Friction is a force that resists motion when two surfaces rub against each other.
- Weight
- Weight is the force of gravity pulling on an object's mass.
Common Mistakes to Avoid
- Facing opposite poles together, which makes the car stick to the track instead of levitate because opposite poles attract.
- Using a car that is too heavy, which prevents hovering because the magnetic repulsion is not strong enough to balance its weight.
- Placing the track magnets unevenly, which makes the car tilt or scrape because the lift force is not balanced from side to side.
- Letting magnets slide or flip during testing, which changes the pole direction and can turn repulsion into attraction.
Practice Questions
- 1 A model maglev car has a mass of 0.12 kg. What is its weight using W = mg and g = 9.8 m/s^2?
- 2 A student uses 6 magnet pairs to lift a 1.8 N car evenly. About how much upward force must each magnet pair provide?
- 3 Explain why a maglev car can move with less friction when it hovers slightly above the track.