Download Magnetic Levitation

Magnetic Levitation
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General Information
Source:
Creator:
NBC Learn
Katie Quinn
Resource Type:
Copyright:
Event Date:
Air/Publish Date:
09/03/2015
09/03/2015
Copyright Date:
Clip Length
Video Science Explainer
NBCUniversal Media,
LLC.
2015
00:04:09
Description
See a pencil float in the air with the help of magnetic force and explore numerous devices that utilize the
power of magnets. This grade 6-8 science story is produced by NBC Learn in partnership with Pearson.
Keywords
Magnets, Magnetic, Electric, Electricity, Magnetism, Magnetize, Current, North Pole, South Pole, Push,
Pull, Attraction, Attract, Repulsion, Repulse, Electromagnet, Electromagnetism, Polarity, Magnetic Field,
Energy, Battery, Wire, Coil, Junkyard, Maglock, Magnetic Lock, Maglev, Magnetic Levitation, Train,
Maglev Train, Shinkansen, Japan, Force, Power, Levitation
Transcript
Magnetic Levitation
KATIE QUINN, reporting:
What if I told you I could make this pencil levitate--literally float--in the air?
With no tricks, and no wires.
Watch this.
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How did I do this? With the power of magnets.
I took two magnets and slid them over the pencil. Then I placed four magnets in this pedestal.
When I aligned the pencil's magnets over the pedestal's magnets...
Voila, a levitating pencil! I can even spin it. Check it out.
Have you ever stopped to think about how magnets work...or how many of the things you use every day
include magnets? Let's take closer a look.
Magnets generate a force. That force is invisible and can push or pull certain objects and make them
move...without touching them.
Every magnet has a north pole and a south pole, which are located at the opposite ends of the magnet.
These magnets are no exception.
The red side is the north pole, and the blue side is the south pole.
If you take two of these magnets and push the north and the south poles together, they connect without
any help.
But, if I flip one of the magnets over and I try and push the two south poles together, they resist and push
apart. They never connect to each other, no matter how hard I push.
Take a look at the levitating pencil again. I lined up all the south poles so they would repel each other,
which makes the pencil levitate. Pretty cool, huh?
Another type of magnet is called an electromagnet. When an electric current is run through a wire, it
produces a magnetic field
To reverse the polarity of the magnetic field, just reverse the direction of the current.
If you wind the wire into a coil, it produces a stronger field.
Another way to make a stronger magnetic field is by wrapping wire around an object. But, the object has
to be something that can be magnetized...like this nail.
You can also change its strength by increasing the electric current running through the wire.
Or by adding more loops.
And if you want the electromagnet to stop working completely, just disconnect it!
Can you think of some of the places where electromagnets are used? Maybe you've seen those huge
electromagnets in junkyards.
Or a maglock, where the strong magnetic field of an electromagnet keeps the door locked. But only until a
key card interrupts the current and allows the door to be opened.
And how about a maglev train? Instead of using wheels and an engine to make it run, a maglev train uses
magnetic force. Maglev is short for magnetic levitation.
Remember our levitating pencil? Well a maglev train works on the same basic principle. It literally floats
above the rails without touching them.
One of the most famous maglev trains is the Shinkansen in Japan that can travel at speeds approaching
500 kilometers per hour, or 310 miles per hour. If a regular train travels at 160 kilometers per hour, it
would take about
three
hours to travel from Boston, Massachusetts to Philadelphia Pennsylvania. But A maglev train like the one
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in Japan would take just a little bit over
one
hour to make the same trip!
Now it's your turn to use the power of magnetic force. Work with a partner to design a device that uses
magnetic force. Make a diagram of your device and be sure to label the north and south poles of any
magnets involved. Have fun!
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