PHY 317K 1st Edition Lecture 22Outline of Last Lecture I. Describe and explain the process of phase changes in terms of molecular behaviorII. Explain in terms of molecular behavior why temperature does not change during a phase changeIII. Specific Latent HeatIV. Solve problems involving specific latent heatsV. Identify factors that affect evaporation rate.Outline of Current Lecture I. QuestionsII. Work in an Ideal-Gas ProcessesIII. Heat, Temperature, and Thermal EnergyCurrent LectureWhat quantities appear in the first law of thermodynamics?A. force, mass, acceleration B. inertia, torque, angular momentum C. work, heat, thermal energy D. work, heat, entropy E. enthalpy, entropy, heatWhat was the original unit for measuring heat?A. BTU B. Watt C. Joule D. Pascal E. CalorieWhat is the name of an ideal-gas process in which no heat is transferred?A. Isochoric B. Isentropic C. Isothermal D. Isobaric E. AdiabaticHeat isA. the amount of thermal energy in an object.B. the energy that moves from a hotterobject to a colder object. C. a fluid-like substance that flows froma hotter object to a colder object. D. both A and B. E. both B and C.The thermal behavior of water is characterized by the value of itsA. heat density. B. heat constant. C. specific heat. D. thermal index.Work in Ideal-Gas ProcessesConsider a gas cylinder sealed at one end by a moveable piston.If we let the piston move in a slow quasi-static process from initial volume Vi to final volume Vf, the total work done by the environment on the gas is w = - p dvIn an isochoric process, when the volume does not change, no work is done.In an isobaric process, when pressure is a constant and the volume changes by ∆V = Vf − Vi, the work done during the process isW =-pdVHeat, Temperature, and Thermal Energy• Thermal energy Eth is an energy of the system due to the motion of its atoms and molecules. Any system has a thermal energy even if it is isolated and not interacting with itsenvironment. The units of Eth are Joules.• Heat Q is energy transferred between the system and the environment as they interact. The units of Q are Joules.• Temperature T is a state variable that quantifies the “hotness” or “coldness” of a system. Atemperature difference is required in order for heat to be transferred between the system and the environment. Theunits of T are degrees Celsius or
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