Thermodynamics!.PPT

Thermodynamics! Kinetic-Molecular Theory Internal Energy Internal Energy vs. Heat Units for Heat Internal vs. “External” Energy Temperature vs. Internal Energy Temperature vs. Internal Energy (cont.) Temperature Scales Absolute Zero the Kelvin Scale Thermal Equilibrium Heat Transfer Processes Conduction Convection Radiation Radiation: Power Temperature Black Body Thermal Conductivity, k SI Units for Thermal Conductivity Cold Tootsies Thermopane Windows Triple pane vs. Double pane R Value Wind Heat Loss Laws of Thermodynamics Zeroth Law First Law First Law (cont.) Second Law Entropy: Statistical Approach Entropy (cont.) Entropy (cont.) Entropy (cont.) Entropy: Statistics Formula Entropy Fluids Entropy Fluids (cont.) Entropy Example 1 Entropy Example 2 Most Probable = Least Useful Change in Entropy Equation Change in Entropy Example Change in Entropy Example (cont.) Second Law Consequences Second Law Consequences (cont.) Heat Engines Refrigerators Specific Heat Specific Heat Equation Calorimetry Calorimetry (cont.) Latent Heat Latent Heat Formula Latent Heat / Specific Heat Example Latent Heat Entropy Internal Energy, Work, Heat Internal Combustion Engine Calorimetry Tigger Thermal Expansion Bimetallic Strip Thermostats Thermal Expansion The Concorde Thermal Expansion Example Credits Suppose our coin system is in macrostate 4 (all heads). This represents maximum order, minimum entropy. Every so often one of the coins is chosen at random and flipped. With each flip there is a 50-50 chance that the macrostate will change. With time (after enough flips), it is doubtful that the system will still be in the minimum entropy state. It is much more likely to be in macrostate 2, the state with the most entropy. The 2nd Law states that during any process the universe moves toward more probably states--states with more entropy. It is possible to decrease the entropy of our coin system by physically turning all tails over so that there