• Introduction to Thermodynamics • Temperature Scales, Absolute Zero • Phase Changes, Equilibrium, Diagram Interlude
Lecture 9 • Introduction to thermodynamics • Temperature scales, absolute zero • Phase changes, equilibrium, diagram Interlude Quiz (Thursday, March 5) • Chapter 21 1st mid-term (Tuesday, March 10) • Chapters 14, 15 (except 15.6), 20 and 21 • diverse topics: start preparing now Thermodynamics (Chs. 16-19) • Next few weeks: transformation of energy from one form to another: e.g. engines convert fuel energy into mechanical; living organisms convert chemical energy of food into kinetic... macroscopic systems instead of particles; temperature (T), pressure (p)...instead of position, velocity... How do pressure, temperature change or work done by engines related to fuel energy used? macro/micro connection: T related to motion of atoms...2nd law... ultimate goal: how heat engines convert heat energy to work • This week bulk properties (T, p) phases of matter; phase changes start micro/macro connection • Today: 3 phases of matter; mass... Solids, Liquids and Gases change between liquild/solid or liquid/gas: phase change • Solids rigid: atoms vibrate, but not free to move; incompressible (atoms as close as can be); crystal (arranged in periodic arrray) or amorphous (random) • Liquids incompressible, but flows/fits shape of container: molecules can slide around each other, but can’t get far apart • Gases freely moving molecules...till collide with each other/wall compressible (lot of space...) State variables parameters describing macroscopic systems e.g. • M mass (M), density (ρ ), p, T...related: e.g., ρ = V change state by changing variables:
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