Applying Technology: Using Energy

8

Applying Technology: Using Energy

27Energy: The

Foundation of Technology

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only.

• 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.


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.


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).


Measuring Power

• Power = Work done (in ft.-lbs.) / Time (in seconds)

• The metric version:• Power (in watts) = Work done (in joules) / Time (in

seconds)


Horsepower

• Horsepower describes the output of many mechanical systems.

• 1 Horsepower = 550 ft.-lbs./sec


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.


What is the difference between work and power?


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.


Forms of Energy

• There are six major forms of energy:


Mechanical Energy

• Mechanical energy is associated with machines.

• Wind and moving water are also sources of mechanical energy.


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 high-

frequency waves of the same amplitude.


Radiant Energy (Cont.)

• Sources of radiant energy include:• The sun. • Objects heated with a flame. • A lightbulb in a lamp.

• Examples of radiant energy:• Radio waves.• Microwaves.• Light.• X rays.• Gamma rays.


Chemical Energy

• Chemical energy is released when a substance is put through a chemical reaction by rapid oxidation (burning), digestion, or reduction.

• Sources of chemical energy:• Petroleum• Natural gas• Coal• Wood• Grains• Biomass.


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.


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.


Nuclear Energy

• Nuclear energy is released when atoms are split during fission or are combined during fusion.


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.


How many ways do we use electrical energy?


Sources of Energy

• There are three types of energy sources.

(Marathon, U.S. Department of Energy)


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.


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.


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.


The Water Cycle


Why is the water cycle important to energy conversion?


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.


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.


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.


• Power plant operators.• Control and monitor boilers, turbines,

and generators in electrical power-generating 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.


What is energy?

The ability to do work.


What is the difference between potential and kinetic energy?

Potential energy is stored energy. Kinetic energy is energy in motion.


How is power calculated?

Power is calculated by dividing the work done by the time taken.


What are the six major forms of energy?

Mechanical, radiant, chemical, thermal, electrical, and nuclear.


Give examples of exhaustible resources.

Petroleum, natural gas, and uranium.


Give examples of renewable resources.

Wood, grains, and biomass resources (garbage, sewage, and waste).


Give examples of inexhaustible resources.

The water cycle, winds, direct solar energy, and geothermal energy.


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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Applying Technology: Using Energy

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