Download Magnetism - Hoover Elementary School

Energy Transfer Unit – Magnetism Notes
Attract- To attract means to pull toward one another. Iron and steel objects are
attracted to magnets.
Magnet- A magnet is a material that has the ability to attract iron, steel, or an
iron alloy.
Repel- To repel means to push away from one another.
Investigation 9 – What materials are attracted to a magnet? In this investigation the
iron nail, paper clip, washer, and safety pin were attracted to the magnet. The plastic
spoon, paper, styrofoam peanut, and rubber band were not attracted to the magnet. The
materials attracted to the magnet were all made of metal. The objects not attracted to
the magnet were not made of metal.
Magnetic- A magnetic material is a substance that is attracted to a magnet and
can act like a magnet.
Magnetically attract- If two objects magnetically attract to each other, they are
pulled toward each other. Iron and steel objects are magnetically attracted to
magnets. When two unlike poles of magnets are placed near each other, they are
magnetically attracted.
Magnetically repel- If two objects magnetically repel each other, they are
pushed away from each. When two like poles of magnets are placed near each
other, they are magnetically repelled.
Investigation 10 – What metals are attracted to a magnet? Not all metals are attracted
to a magnet. The data shows that some materials made of metal were not attracted to
the magnet. Magnets attract objects made of iron, cobalt, and nickel. Aluminum, brass,
and copper are not attracted to a magnet.
What effect does distance between a magnet and magnetic material have on attraction?
The magnetic field expands beyond the actual magnet. Some magnets are stronger than
others and will attract objects from a greater distance.
Will a magnet continue to attract objects with a barrier placed between them? The paper
clip was attracted to the magnet through the thin material and not through the thick
block. The paper clip moved toward the magnet through the cloth, paper, and
cardboard. There was no magnetic attraction through the wooden block.
Iron Fillings – Iron fillings are shaved bits of iron metal. Iron fillings are used
to demonstrate magnetic field, magnetic poles, and lines of force.
Lines of force – Lines of force are the invisible lines that make up a magnetic
field. The lines of force are closer together and stronger at the poles of a magnet.
Magnetic Field – A magnetic field is the area of attraction and repulsion that
surrounds a magnet.
Magnetic Pole – A magnetic pole is a place on a magnet where the magnetic
effect is the strongest. The two ends of a bar magnet are its poles.
Investigation 11 – How can you tell that magnets are strongest at the poles? From the
data collected the ends of a bar magnet appear stronger because they attracted the
greatest number of paper clips.
How can you tell a magnet has two poles? You can tell a magnet has two poles because
more paper clips are attracted to both ends of the magnet than anywhere else on the
magnet.
Investigation 12 – What is observed when like poles of magnets are placed near each
other? Like poles (north pole to north pole or south pole and south pole) magnetically
repel or push away from each other.
What is observed when unlike poles of magnets are placed near each other? Unlike or
opposite poles (north pole and south pole) are magnetically attracted to each other.
Compass – A compass is a tool that uses a magnetic needle to indicate direction
on the Earth’s surface by pointing toward the north.
Investigation 13 – Which way is north? If you suspend a bar magnet by fishing line
the magnet’s north seeking pole will face north. The colored end of a compass needle
points north even when if the dial of the compass is not turned toward north. The
compass needle continues to point north if you turn the compass. The compass needle is
like a free swinging magnet because they both have poles. The north seeking pole of the
compass needle and the north seeking pole of the magnet both point to the north.
Electromagnet – An electro magnet is produced when electricity flows through
a coil of wire wrapped around an iron bar. It acts like a magnet.
Investigation 14 – How can electricity be used to produce heat and a magnetic field?
An electromagnet can be made by wrapping a wire many times around an iron nail. The
nail is then connected to a battery. As long as the wire is connected to the battery the
nail is able to pick up paper clips. If you disconnect the wire from one end of the battery
the paper clips fall off. The paper clips are no longer attracted to the nail because the
electrical circuit from the battery was open or incomplete. The battery and the wire
coiled around the iron nail shows how electricity can produce magnetism.