Magnets & Static Electricity

Before Video

• Yes. Non-contact forces include magnetic, electric (electromagnetic and static) and gravitational forces.
  

• No. Magnetic fields extend beyond the magnet causing forces to be applied at a distance.

• Magnets are attracted to certain types of metal like iron, nickel and cobalt.

• The attraction of metal to magnets (such as a paper clip sticking to a magnet) is evidence that magnets exert a force. Iron filings or ferrofluid can also provide evidence of the magnetic field.

After Video

• We know they are there because magnets push and pull magnetic materials. We can also visualize magnetic fields using certain materials such iron filings or ferrofluid seen in the video.

• An aluminum can is not attracted to a magnet. We see this during the “magno-board” investigation. Only certain kinds of metal like iron, nickel and cobalt are attracted to a magnet.

• The neodymium magnets are set up with opposite poles facing each other so that they are attracted to each other. These types of magnets are VERY strong and when they are pulled together with a lot of force, fruit can be smashed!

• The closer a magnet is to an object, the stronger the force.

• An iron nail wrapped in wire is not magnetic, but when electricity from a battery flows round and round through the coil of wire it creates a magnetic field. When the electricity stops flowing the magnetic field disappears and the nail is no longer magnetized.

• The balloon and plastic bag have the same charges. Evidence: they repel each other.

• Magnets have North and South poles. Like poles repel while opposite poles attract. Similarly, when hairs become charged with like charges using the Van de Graff generator, they repel each other.

• Magnets can solve all kinds of every day problems. Holding objects to a refrigerator or whiteboard without leaving marks. Picking up small metal objects off the floor. If you are lost a compass contains a magnet that can tell you which direction is north. Magnets are also used to separate metal items from paper recycling. Some power cord use magnets to attach to the device they are charging.

• When two objects have the same electric charge they push apart. When two objects have opposite electric charges, they are pulled together.