Transcript Gravity, Electricity, & Magnetism

Gravity, Electricity, &
Magnetism
S8P5. Students will recognize characteristics
of gravity, electricity, and magnetism as
major kinds of forces acting in nature.
Enduring Understandings
Students will understand that:
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Electric forces arise from the
movement of electrical charge.
Magnetic forces arise from the
movement of electrical charge.
An electric circuit allows electrons to
flow from a negative pole to a positive
pole.
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Series and parallel circuits can be
used to control the amount of
electric energy produced.
Every object exerts gravitational
force dependent upon its mass and
distance from other objects.
Gravity
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The force that attracts all objects
toward each other.
Gravity depends on two factors:
Mass of objects
 Distance between objects
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Mass
Amount of matter in an object
Weight
Force of gravity on an object
Electricity
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The collection or flow of electrons in
the form of an electric charge.
Electrons are a negatively charged
particle located outside the nucleus of
an atom.
Static Electricity
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Is the charge that stays on an object.
Unlike charges (+,-) attract each other, and like
charges (+,+), (-,-) repel each other.
Materials affect charge movement
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Conductors- a material that allows an electric
charge to pass through it easily.
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Examples: iron, steel, copper, & aluminum
Insulators- a material that does not allow a
charge to pass through it.
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Examples: plastic & rubber
Electric Current
The steady flow of electricity.
 A current will move along a wire or a
path called a circuit.
 Circuit means “to go around.”
 There are two types of circuits
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Series Circuit
Parallel Circuit
In which direction does the current
flow?
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From the Negative
terminal to the
Positive terminal of a
cell.
Types of Circuits
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Series Circuit is a circuit
that has only one path
for the current.
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Parallel Circuit is a circuit
that has more than one
path for current to travel.
Short Circuits
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An unintended path
 A short circuit will cause
connecting one part of a large amounts of current
circuit with another.
to flow in a circuit and
overload the circuit.
 They are very
dangerous.
 The wires on a circuit
can melt and then
cause a fire.
Magnetism
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A push or pull exerted by a magnet.
There are two poles.
North
 South
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If you cut a magnet in half, you do not separate
one pole from the other. Both pieces will have
two poles.
Opposites attract
 Like poles push away from each other.
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Magnetic Field
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The area surrounding the
magnet is the magnetic field.
Where the lines are the
closest, the magnetic force is
the strongest.
Electricity & Magnetism
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Passing a current through a piece of wire causes
a magnetic field to form around a wire
(electromagnetism).
The strength of the magnetic field could be
greater if you put a piece of copper inside the
wire. This is called an electromagnet.
Electromagnets
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Their magnetism can
be turned on or off.
Stopping the flow of
electric current through
the wire coil stops the
magnetic field.
How do we change the
strength of the
electromagnet?
To INCREASE To DECREASE
Increase the
strength of the
current
Decrease the
strength of the
current
Add more coils
of wire
Use fewer coils
of wire
Increase size of
iron core
Decrease size of
iron core