Ten Facts about Magnets
(from the book Driving Force)
1. North poles point north, south poles point
2. Like poles repel, unlike poles attract.
3. Magnetic forces attract only magnetic materials.
4. Magnetic forces act at a distance.
5. While magnetized, temporary magnets act like permanent
6. A coil of wire with an electric current flowing through it
becomes a magnet.
7. Putting iron inside a current-carrying coil increases the
strength of the electromagnet.
8. A changing magnetic field induces an electric current in a
9. A charged particle experiences no magnetic force when
moving parallel to a magnetic field, but when it is moving perpendicular to the
field it experiences a force perpendicular to both the field and the direction
10. A current-carrying wire in a perpendicular magnetic field
experiences a force in a direction perpendicular to both the wire and the
The Tricky Triangle
Solve this by placing a magnetic marble in each hole. You'll find it;s very difficult and addictive.
The monkey stays on the track because of the magnets on the axis of the wheel.
They are strong enough to hold the wheel to the track when its moving. But when
gravity and friction slow the wheel down enough to allow centripetal force to
overpower the magnetic force, it will fly off the rails on the outside curve
farthest from the handle.