Magic Train Puts Kids on Track with Physics of Magnetism
Assembling a simple wooden train and track with cleverly placed magnetic strips lets kids experiment with a train that levitates off the track and zips effortlessly from one end to the other when pushed. What happens when you add a bit of weight? Put the science question to the test in this fun hands-on science activity and experiment.
The allure of a magic trick is something pretty cool to most kids. The quarter pulled from behind the ear. It's a classic sleight of hand passed down by generations. The finger that appears to be separated into two parts at the knuckle, able to be slid side to side. (That one has been used to gross out and entertain plenty of kids.) Card tricks. Bunnies from hats. People that vanish from a cube. Magic appeals to us on some level where suspension of disbelief wars with our intellect, our logic, and our puzzle-solving skills. Part of enjoying a trick may, in fact, be trying to figure out how it was done, how it is possible, what really accounts for what we saw, and how to do it ourselves!
That science is full of everyday things that seem magical is a cool twist on sleight of hand and illusion. The more you understand science, the more you can explain what is going on in a process that seems "magical."
In the Harry Potter books, the train that transported the kids to and from school each year involved walking right through a wall to reach the 9 3/4 platform at King's Cross Station. That's a special kind of magic—the fantasy kind. Science can't explain it. The train on the other side of the wall, the shiny red Hogwarts Express, appears to be fairly normal, a fast-moving steam locomotive on tracks.
But there are other real-world kinds of trains that may seem to have a bit of magic to them. Maglev trains are ones that seem to hover or float above a track rather than rolling across it. Maglev trains may look similar to monorail trains, but a maglev train specifically levitates and is powered by electromagnetic forces. Plus, a maglev train doesn't have wheels!
It may look like magic, but it isn't. A maglev train is lifted by the way magnetic fields positioned a certain way repel one another. As the fields push away from each other, the train lifts off of the track and floats above the rail. Because it floats, when the train moves, there is no friction of train wheels against train tracks, so a Maglev train can go faster than a traditional train that rolls on wheels. There are still air forces (like drag) to take into account, but some maglev trains are capable of speeds greater than 300 mph.
Bringing the Magic Home
Studying magnets and magnetism is often exciting for elementary students. The way magnetic fields can be oriented to repel or attract one another can provide lots of entertainment value as students explore magnetism and learn more about how magnets work. You can extend magnetism discussions with a wide range of hands-on science projects and activities that can be done at home or at school. From testing the strength of an electromagnet to building a simple motor, students can explore magnetism with projects that remove the "magic" but still have plenty of "wow" factor.
For a different spin on magnetism, building a simple Maglev train is a fun way to couple a creative project with a science activity. The Magic Bullet Train kit, available in the Science Buddies Store, is a great way to get kids talking about and actively exploring magnetism and the real-world application of magnetic fields in levitating trains. Two generic magnets on a table may push away from one another, but they probably don't move far. That the same principle can be used to lift a train is pretty cool science!
Using the do-it-yourself maglev train kit, students first make their own bullet train by sanding down and painting a wooden block that will be the "train" in the experiment. How far you go with this step is up to you and your kids. It isn't easy to sand the rectangular block into something that really looks like a bullet, but spending time sanding, shaping, and then painting, decorating, and personalizing the train is part of the fun of the project! Just be sure that you don't sand the "bottom" of the train. You want to leave the bottom edge untouched.
All Aboard for Magnetic Science!
When using the Magic Bullet Train kit as a family science activity, the "building" of the train is the bulk of the activity. The small directions booklet that comes with the train kit walks you step by step through assembling the wooden rail system, adding the magnetic strips, and attaching the girders to your painted wooden train. Be careful during assembly to line things up as shown, to adhere the magnetic strips on the proper sides of the wooden rails and train, and to attach the girders as low to the bottom of the train as you can to ensure the train hovers as high as possible above the wooden rail.
Unlike a real-world maglev train, the wooden train kit relies on the standard magnetic field between the magnetic strips. There is no electromagnetism adding to the field, so don't be surprised if the train doesn't hover as high as you expect—or does not seem to hover the first time. It can take some fiddling with the placement of the girders to ensure the train hovers properly. But once you get things set up properly, a simple push of the train sends it gliding smoothly across the track. Your kids will see and feel the lack of track friction as the train glides across!
It looks like magic!
Having built the system, your young engineers will be in on the trick and able to explain how the magnetic strips work hold the train off the track. You can talk, too, about the design of the train and what holds the train "on" the track and why certain aspects of the train's design are important so that it won't fall off—design factors that help prevent accidents.
Because of the small size of the experiment and the limited number of parts (just the train and the track, once assembled), this is a great science experiment to take to school and show off. Check with your teacher first, but chances are that a small demonstration of magnetism in the form of a maglev train will be welcome and can be squeezed in during some part of the day.
Building the train is a great hands-on experiment in and of itself, but if there is a science fair assignment on hand, a student can use the train kit as the basis for a full science investigation. The The Amazing Floating Train: How Much Weight Can a Maglev Train Hold? project at Science Buddies guides students in an exploration of the relationship between weight and a maglev train's ability to levitate. It makes sense that a floating train will have maximum weight limits. But what happens when those limits are exceeded? In the The Amazing Floating Train science project, students put it to the test with their own maglev train and plastic cups filled with varying amounts of water.
You might find other ways to vary the project, too. Could you experiment with stronger magnetic strips? What would happen if you did? The "Make It Your Own" tab also contains a challenge to student engineers—install a magnetic "brake" system at the end of the track!