8
Applying Technology:
Using Energy
27
Energy: The
Foundation of
Technology
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Recall the definition of energy.
Compare potential and kinetic energy.
Compare energy, work, and power.
Recall the six major forms of energy.
Give examples of exhaustible, renewable,
and inexhaustible energy sources.
• Explain how energy technology can make
our lives better and how energy technology
can cause damage.
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Types of Energy
• Energy is used in human tasks, like walking.
• Kinetic energy is when a sail captures the wind to
power a boat.
• Potential energy is stored energy in a flashlight
battery, a gallon of gasoline, etc.
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Measuring Work
• Work is measured by multiplying the weight
moved by the distance moved.
• Force (Weight) x Distance = Foot-pounds (ft.-lbs.)
• In the metric system, work is measured in joules (J).
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Measuring Power
• Power = Work done (in ft.-lbs.) / Time (in
seconds)
• The metric version:
• Power (in watts) = Work done (in joules) / Time (in
seconds)
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Horsepower
• Horsepower describes the output of many
mechanical systems.
• 1 Horsepower = 550 ft.-lbs./sec
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Types of Horsepower
• An engine or motor rarely reaches its maximum or
indicated horsepower.
• Brake horsepower is delivered at the rear of an
engine.
• Drawbar horsepower is delivered to the hitch of
tractors.
• Frictional horsepower is the power needed to
overcome the internal friction of the device.
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What is the difference between work and power?
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Wattage Rating
• Wattage rating in an electrical apparatus:
• P (power in watts) = I (current in amperes) x E
(electromotive force in volts)
• One kilowatt-hour is the work that 1000 watts will
complete in one hour.
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Forms of Energy
• There are six major forms of energy:
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Mechanical Energy
• Mechanical energy is
associated with machines.
• Wind and moving water
are also sources of
mechanical energy.
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Radiant Energy
• Electromagnetic waves produce radiant energy.
• They range from long waves to short waves.
• Cool objects give off longer waves than hot objects.
• Low-frequency waves contain less energy than highfrequency waves of the same amplitude.
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Radiant Energy (Cont.)
• Sources of radiant energy
include:
• The sun.
• Objects heated with a flame.
• A lightbulb in a lamp.
• Examples of radiant
energy:
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Radio waves.
Microwaves.
Light.
X rays.
Gamma rays.
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Chemical Energy
• Chemical energy is released • Sources of chemical
when a substance is put
energy:
through a chemical reaction
• Petroleum
by rapid oxidation (burning),
• Natural gas
digestion, or reduction.
• Coal
• Wood
• Grains
• Biomass.
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Thermal Energy
• Thermal energy cannot be seen directly, but is
usually felt.
• It is created by the rapid internal movement of
atoms in a substance.
• The energy strikes a surface and elevates its
temperature.
• It provides energy for heating systems and some
electrical generating plants.
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Electrical Energy
• Electrical energy is used as a basic source for
other forms of energy.
• It is often converted into heat energy or into light
energy.
• It is associated with electrons moving along a
conductor (for example, a wire).
• Lightning is a natural source of electrical energy.
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Nuclear Energy
• Nuclear energy is released when atoms are split
during fission or are combined during fusion.
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Energy Is Interrelated
• All six forms of energy are related to one
another.
• Radiant energy can be used to produce heat. This is
what happens when you get sunburned.
• Fire causes fuel to undergo a chemical action. Coal
can be turned into carbon dioxide and water.
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How many ways do we use electrical energy?
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Sources of Energy
• There are three types of energy sources.
(Marathon, U.S. Department of Energy)
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Exhaustible Energy Resources
• Exhaustible energy resources cannot be replaced
and have a limited supply on earth.
• Include fossil fuels such as petroleum, natural gas, and
coal.
• Uranium, a radioactive mineral, is another exhaustible
energy resource.
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Renewable Energy Resources
• The supply of renewable energy resources is
affected by human propagation, growing, and
harvesting activities.
• Biotechnology, such as gene modification, improves the
types and quantities of resources grown.
• Biomass materials can be used as energy resources
and burned as biofuels or converted into methane to
produce biogas.
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Inexhaustible Energy Resources
• Inexhaustible energy resources are associated
with the solar weather system:
• One-third of the sun’s radiant energy that reaches the
earth is reflected back into space.
• About two-thirds of solar energy is absorbed by the
atmosphere.
• About one-fourth of this energy powers the water cycle.
• Inexhaustible energy resources produce energy
through hydroelectric power generators, wind
generators, and solar converters.
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The Water Cycle
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Why is the water cycle important to energy
conversion?
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Solar Energy and Wind
• Solar energy heats the land.
• Different amounts of solar energy strike various
areas of the earth, creating temperature
differences.
• Warmer air rises and is replaced by cooler air.
• This creates air movement, or wind.
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Geothermal Energy
• Geothermal energy uses water that has been
heated by the earth.
• It is tapped by wells and used to heat buildings or
power electrical generators.
• The geysers at Yellowstone National Park are
produced by geothermal energy.
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Effects of Energy Technology
• People must look at both the good and bad
effects of technology.
• Fuels and biomatter burn, creating the power that
drives our society, but releasing dangerous
pollutants into the air, land, and water.
• Nuclear power plants do not leak toxic gases, but
their waste is more dangerous and longer lasting.
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• Power plant operators.
• Control and monitor boilers, turbines,
and generators in electrical powergenerating plants.
• Monitor instruments to maintain
voltage and regulate electricity flow.
• Strong math and science background
is required, as well as extensive
on-the-job and classroom instruction.
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What is energy?
The ability to do work.
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What is the difference between potential
and kinetic energy?
Potential energy is stored energy. Kinetic
energy is energy in motion.
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How is power calculated?
Power is calculated by dividing the work
done by the time taken.
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What are the six major forms of energy?
Mechanical, radiant, chemical, thermal,
electrical, and nuclear.
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Give examples of exhaustible resources.
Petroleum, natural gas, and uranium.
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Give examples of renewable resources.
Wood, grains, and biomass resources
(garbage, sewage, and waste).
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Give examples of inexhaustible resources.
The water cycle, winds, direct solar energy,
and geothermal energy.
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What are the beneficial and harmful effects
of energy technology?
Energy drives our society and produces the
goods needed to survive. Technology can
waste energy resources, pollute the
atmosphere, and create human suffering.
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