CH 304K 1st Edition Lecture 27 Outline of Last Lecture I. Thermodynamics definitions Outline of Current Lecture II. Types of EnergyIII. Heat and TemperatureIV. CombustionV. First Law of ThermodynamicsVI. Second Law of ThermodynamicsVII. EntropyCurrent LectureTypes of Energy- Kinetic Energy: energy of motion; KE = ½ mv2- Mechanical Energy: work- Electrical Energy (another kind of work): flow of electrons through an electrical conductor- Thermal Energy (Heat): from random motion of particles of matter- Potential Energy (“stored” energy): due to position or composition of matter- Electromagnetic radiation: lightHeat and Temperature- Average thermal energy of the particles- Dictates which way heat energy flows from warmer body to cooler oneCombustionThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Exothermic, self-sustaining chemical reaction which involves a fuel reacting with an oxidant (it releases heat, the heat keeps the reaction going)- 3 parts: oxygen, heat, fuel- fuels contain chemical potential energy- combustion converts this energy into other forms such as heat, light, soundFirst Law of Thermodynamics- energy is not created or destroyed; merely converted from one form to another- total amount of energy is constant Converting Energy- we desire energy as heat or work in a form that can be controlled, transported, and stored- almost all conversion starts as chemical potential energy- in energy conversion, some energy is lost- “lost” means it is not converted into the desired form- overall efficiency= (electrical energy produced/heat energy from fuel) x 100%- power plant efficiency is usually between 35-50%Second Law of Thermodynamics- any spontaneous (feasible) process, the overall entropy of the universe increases- unusable energy= entropy- perpetual motion machines do NOT existEntropy- measure of positional disorder on an atomic scale- analogies: shuffled cards, jumbled socks- examples: gases mix and don’t unmix by themselves, sugar doesn’t un-dissolve from water by itself- measure of dispersion of heat energy- all matter above absolute zero is
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