chapter 5 intro - What are the different forms of energy?...

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What are the different forms of energy? Energy has a number of different forms, all of which measure the ability of an object or system to do work on another object or system . In other words, there are different ways that an object or a system can possess energy. Kinetic Energy: Consider a baseball flying through the air. The ball is said to have "kinetic energy" by virtue of its velocity. • KE is energy that is being expressed – You can see that it is has energy because it can do " work " on an object on the ground if it collides with it (either by pushing on it and/or damaging it during the collision). • KE = ½ mv 2 Potential Energy Potential Energy is the energy that is waiting to be expressed. Consider a book sitting on a table. The book is said to have "potential energy" because if it is nudged off, gravity will accelerate the book, giving the book kinetic energy. – Because the Earth's gravity is necessary to create this kinetic energy, and because this gravity depends on the Earth being present, we say that the "Earth- book system" is what really possesses this potential energy, and that this energy is converted into kinetic energy as the book falls. Thermal energy (heat energy) This is the primary form of energy discussed in Ch 5 Consider a hot cup of coffee. The coffee is said to possess "thermal energy", or "heat energy" which is really the collective, microscopic, kinetic energy of the molecules in the coffee (the molecules have kinetic energy because they are moving and vibrating. • Temperature is really a measure of how much kinetic energy something has. – The higher the temperature, the faster the molecules are moving around and/or vibrating, i.e. the more kinetic energy the molecules have.
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Electrostatic energy • The energy by which oppositely charged particles repel or attract one another • Electrostatic energy is proportional to Where Q is the magnitude of the charge on each particle and d is the distance separating these particles Q 1 Q 2 d Chemical Energy Consider the ability of your body to do work. The glucose (blood sugar) in your body is said to have "chemical energy" because the glucose releases energy when chemically reacted (combusted) with oxygen. – Your muscles use this energy to generate mechanical force and also heat. Chemical energy is really a form of microscopic potential energy. These atoms get rearranged in chemical reactions, releasing or adding energy to their bonds. Electrical Energy Some material, particularly metals, have certain electrons that are only loosely attached to their atoms. They can easily be made to move from one atom to another if an electric field is applied to them. When those electrons move among the atoms of matter, a current of electricity is created. This is what happens in a piece of wire when an electric field, or
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This note was uploaded on 03/03/2010 for the course CHEM CHEM400 taught by Professor Stewart during the Spring '10 term at American River.

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chapter 5 intro - What are the different forms of energy?...

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