UNIT FIVE: Electricity and Magnetism Chapter 16 Electricity Chapter 17 Magnetism.
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Transcript UNIT FIVE: Electricity and Magnetism Chapter 16 Electricity Chapter 17 Magnetism.
UNIT FIVE: Electricity and Magnetism
Chapter 16 Electricity
Chapter 17 Magnetism
Chapter Seventeen: Magnetism
17.1 Properties of Magnets
17.2 Electromagnets
17.3 Electric Motors and Generators
17.4 Generating Electricity
Chapter 17.4 Learning Goals
Review the meaning of mechanical power
and liken it to electrical power.
Compare and contrast renewable and
nonrenewable sources of electrical
energy.
Discuss methods of electrical energy
conservation.
17.4 Generating Electricity
Electricity is made in a power plant.
Most power plants burn fossil fuels
(natural resources like coal, oil, or
natural gas) to produce heat.
17.4 Generating Electricity
Next, this heat is used to boil water.
The steam from the boiling water turns a
turbine.
The turbine turns a generator which produces
electricity.
17.4 Electricity from fossil fuels
A nonrenewable resource is not replaced
as it is used.
Because it takes so long for these
resources to form, someday we will not
have enough fossil fuels to produce the
electricity we need.
The three major fossil fuels are coal, oil,
and natural gas.
The United States gets about 19% of its electricity
production from nuclear power plants.
17.4 Electricity from nuclear energy
The main advantage of
using nuclear energy to
produce electricity is
that it doesn’t pollute
the air like fossil fuel
power plants do.
17.4 Electricity from nuclear energy
Storage of nuclear waste has
always been a major
disadvantage of nuclear power
plants.
Uranium fuel from the reactor
stays dangerously radioactive
for a long time.
17.4 Electricity from renewable
resources
A renewable resource can be replaced
naturally in a relatively short period of
time.
The Sun and wind are
renewable resources
that can be used as
energy sources.
17.4 Electricity from renewable
resources
It is also possible to use:
moving water (hydroelectric)
hot spots near Earth’s surface (geothermal)
fuels made from once-living things like
wood or corn (called biomass) or
tides to produce electricity.
17.4 Hydroelectric power
A hydroelectric (or
hydropower) plant
uses energy from
falling water to
generate electricity.
17.4 Geothermal and biomass
Geothermal power plants use Earth’s
internal heat energy, in the form of water
or steam, to produce electricity.
A geothermal heat pump system takes
advantage of the relatively constant
temperature of Earth’s shallow ground.
17.4 Geothermal and biomass
Biomass is organic material from plants
or animals.
In waste-to-energy plants, renewable
solid waste is burned to produce
electricity, which also creates some air
pollution.
17.4 Wind and solar energy
California was the
first U.S. state to
build large wind
farms.
Wind farms can
disturb natural
habitats, and can
perhaps scar a large
area of scenery.
17.4 Wind and solar energy
The Sun’s energy
is often called
solar energy.
A solar cell (also
known as a
photovoltaic cell)
can convert solar
energy to
electricity.
17.4 Electrical power
Electrical power is
measured in watts, just
like mechanical power.
Electrical power is the
rate at which electrical
energy is changed into
other forms of energy
such as heat, sound, or
light.
17.4 Electrical power
Utility companies charge customers for the
number of kilowatt-hours (kWh) used each
month.
A kilowatt-hour is a unit of energy.
The number of kilowatt-hours used equals the
number of kilowatts multiplied by the number of
hours the appliance was turned on.
17.4 Electrical power
There are many
simple things you
can do to use less
electricity.
When added up,
these simple things
can mean many
dollars of savings
each month.
Under the Sea
Have you ever wondered what
it would be like to take a “walk”
on the seafloor? Engineer Jim
Varnum gets to go “down
under” regularly, because he is
a pilot of an extremely complex
robot called Jason II. This
robot dives deep into the ocean
and is used to take pictures
and collect data from the
seafloor.