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T E C H N O L O G Y by R. Thomas Wright ERC’s Notes: Chapter 27, Energy: The Foundation of Technology Thursday, April 30, 2015 Chapter 27: Energy: The Foundation of Technology Learning Objectives: 1. Be able to define ENERGY 2. Identify the difference between energy, work and power. 3. Describe the difference between potential and kinetic energy. 4. Identify the six major forms of energy 5. Identify exhaustible, renewable, and inexhaustible energy sources 6. Explain how energy technology can make our lives better and how energy technology can cause damage. ENERGY IS THE ABILITY TO DO WORK
1. Kinetic Energy is the energy of motion.
2. Potential Energy is stored energy, the
ability to do work in the future.
THE LAW OF ENERGY CONSERVATION
(AKA The First Law of Thermodynamics)
Energy cannot be created or destroyed; it can
only be changed from one form to another.
Energy is the ability to do work. Moving an object a distance is the definition of work. Power is work per unit time, the rate in which work is done. When an object is moving it is said to have kinetic energy, the energy of motion. When an object is stationary, yet has the ability to move, if there is a change in force, that object is said to have potential energy. Energy is the ability to do work or produce change. Kinetic Energy is a force doing work. Kinetic Energy is energy in motion. Potential Energy is the ability of a force to do work in the future. Potential energy is stored energy due to position or structure. Work is the movement of an object a distance. Work is applying a force that moves a mass a distance in the direction of the applied force. Foot‐pound is a unit of work, 1 pound moved one foot, Imperial units. Joule (J) is a unit of work, 1 newton moved one meter, metric units. Power is the rate in which work is completed or energy is used. Horsepower (HP) is the unit of measurement for power, 1 HP = 550 foot‐pound / second, in Imperial units. Watts (W) is the unit of measurement for power in the metric system, 1 newton‐meter / second = 1 J/s Kilowatt (KW) is the comparable measure of power to horse power. Motion, heat, light and sound are byproducts of energy. Energy exists in six major forms. 1,000 W = 1 KW = 0.75 HP 6 Major Forms of Energy
Organic is matter produced from once living plants or animals. 1. Radiant energy is sunshine. Sunshine is electromagnetic waves. Radiant energy is more than visible light and includes x‐ray, radio waves and other wave forms. Fossil Fuel is an energy source from buried organic matter. 1KW = 1000 J/s Biomass is when organic matter is included as a fuel source. Biofuels is organic matter uses as fuel, to produce energy. Biogas is gas produced from decaying organic matter. Figure 1: Electromagnetic Spectrum
Chapter_27_Energy_The_Foundation_of_Technology.docx Exhaustible means the something can run out, or is limited. Inexhaustible means the something cannot run out, or is unlimited. T E C H N O L O G Y by R. Thomas Wright ERC’s Notes: Chapter 27, Energy: The Foundation of Technology Thursday, April 30, 2015 2. Mechanical energy is the sum of potential and kinetic energies.1 Mechanical energy is the movement or potential movement of an object. Wind, water and wheels are a few things that produce mechanical energy. 3. Thermal or heat energy results from the movement of atoms within matter. Heat energy is produced by the rubbing of moving parts together. 4. Chemical energy is released from the making and breaking of atomic bonds in molecules.2 Chemical energy is stored within matter and released during chemical reactions. The change in form releases energy. Food, oil, and garbage burning contain chemical energy. 5. Electrical energy is electrons moving along a conductor. Electricity produces both thermal and mechanical energy. Electrical energy lights and heats our homes and business. 6. Nuclear energy is produced by splitting or joining atoms. Splitting and joining atoms generates large amounts of heat. Fission is splitting atoms. Fusion is the joining atoms together. Nuclear energy powers the US Naval submarines and aircraft carriers. Sources of Energy
There are two groups of energy sources, renewable and unrenewable. Figure 2 shows US energy use in 2012. 90.6% of our energy is from nonrenewable sources, leaving only 9% from renewable sources. Biomass is organic matter used as a fuel source. Grasses, wood, other plant material, waste from humans and animals would be considered as biomass. Biomass is a can be constantly renewed and accounts for 4.6% of our energy. The solar weather cycle, the sun, water and wind are inexhaustible source of energy. But we have not been able to cheaply produce electricity from these sources on a large Figure 2: US Energy Consumption of Energy by Source, 2012
scale. Another problem how is http://tinyurl.com/US‐2012‐Energy‐Consumption, accessed 2014‐05‐
generated electricity stored 08
until it is used? Currently only 4.6% of our energy come from renewable sources. In 2012, nonrenewable fuels created the bulk of our energy. Fossil fuels produce 82.1% of our energy. Living matter buried and decayed over time yield fossil fuels. Petroleum, natural gas and coal are fossil fuels and nonrenewable. Uranium, the fuel for nuclear power generated 8.5% of our energy. Uranium is a heavy metal mined from the earth or recovered from seawater.3 Limited sources, fossil fuels and Uranium create our energy. 1
http://www.buzzle.com/articles/types‐of‐energy.html accessed 2014‐05‐06 http://www.buzzle.com/articles/types‐of‐energy.html, Chemical Energy, accessed 2014‐05‐06 3
http://tinyurl.com/What‐is‐Uranium, What is Uranium? Accessed 2014‐05‐08 2
Chapter_27_Energy_The_Foundation_of_Technology.docx