Scten 210 Unit 3
1
ABSTRACT
Energy is defined as the ability to do work. Work is done when energy is transferred from one system to another and may take on various forms. The law of the conservation of energy states that energy may neither be created nor destroyed. Therefore the sum of all the energies in a system is a constant.
Energy may be either potential or kinetic. Potential energy (PE) is energy stored and ready for use. A car stopped at the top of a hill and a water balloon dangling out of an upstairs window have potential energy. Potential energy is measured by the amount of work the object can perform. The other form of energy is kinetic energy (KE). Kinetic energy is the energy of motion. A car rolling downhill and a water balloon falling towards its target have kinetic energy. Because of its greater mass, a falling car has more kinetic energy than a falling water balloon. Similarly, because of its greater velocity, as water balloon that is thrown down will have more kinetic energy than one that is simply dropped from the same height. As these examples show, potential energy can become kinetic energy. Kinetic energy can also be transferred from one object to another: imagine a car or the water balloon striking a ping pong ball and sending it flying. Recall also that kinetic energy comes in six forms - chemical, electrical, radiant, mechanical, nuclear, and thermal- and that each of these forms can be converted into any of the other forms. For example, a battery converts chemical energy into electricity, and a light bulb converts electricity into light and heat.
Not all energy conversions are a simple as turning on a light bulb. A power plant that uses coal to generate electricity for your home is a complex system that converts the chemical energy in coal into thermal energy, mechanical energy, and then electrical energy.
2
There are many pros and cons for all known sources energy. For instance, if we take the subject of fossil fuel there are so
ABSTRACT
Energy is defined as the ability to do work. Work is done when energy is transferred from one system to another and may take on various forms. The law of the conservation of energy states that energy may neither be created nor destroyed. Therefore the sum of all the energies in a system is a constant.
Energy may be either potential or kinetic. Potential energy (PE) is energy stored and ready for use. A car stopped at the top of a hill and a water balloon dangling out of an upstairs window have potential energy. Potential energy is measured by the amount of work the object can perform. The other form of energy is kinetic energy (KE). Kinetic energy is the energy of motion. A car rolling downhill and a water balloon falling towards its target have kinetic energy. Because of its greater mass, a falling car has more kinetic energy than a falling water balloon. Similarly, because of its greater velocity, as water balloon that is thrown down will have more kinetic energy than one that is simply dropped from the same height. As these examples show, potential energy can become kinetic energy. Kinetic energy can also be transferred from one object to another: imagine a car or the water balloon striking a ping pong ball and sending it flying. Recall also that kinetic energy comes in six forms - chemical, electrical, radiant, mechanical, nuclear, and thermal- and that each of these forms can be converted into any of the other forms. For example, a battery converts chemical energy into electricity, and a light bulb converts electricity into light and heat.
Not all energy conversions are a simple as turning on a light bulb. A power plant that uses coal to generate electricity for your home is a complex system that converts the chemical energy in coal into thermal energy, mechanical energy, and then electrical energy.
2
There are many pros and cons for all known sources energy. For instance, if we take the subject of fossil fuel there are so
References: Environmental Science: Toward a Sustainable Future, 11th Edition, Wright, Pearson, 2011 The Law of Conservation of energy, Retrieved at, http://library.thinkquest.org/2745/data/lawce1.htm, 8/1/12 can receive an immediate tax incentive Fossil fuel pros and cons, Retrieved at, http://www.fossilfuel.co.za/Fossil-Fuel-Pros-And-Cons.aspx, 8/5/12 Nuclear Energy pros and cons, Retrieved at, http://members.tripod.com/funk_phenomenon/nuclear/procon.htm, 8/5/12 Wind Power pros and cons, Retrieved at, http://www.triplepundit.com/2012/06/wind-power-pros-cons/, 8/6/12 Biofuel pros and cons, Retrieved at, http://environment.about.com/od/fossilfuels/a/biofuels.htm, 8/6/12