PHYS 1750: SELECTED TOPICS in PHYSICS
LECTURE 21. Thermal Physics.
| 12.1. | Temperature | ||
| 1. | Concept | ||
| Temperature Scales | |||
| a. | "Absolute zero" = -273 C = -460 F | ||
| b. | Degrees Kelvin | ||
| 3. | Zeroth law of thermodynamics: | ||
| a. | Heat energy flows from hot to cold, and | ||
| b. | Two objects in thermodynamic equilibrium have the same temperature. | ||
| 12.3. | The Ideal Gas | ||
| 1. | PV = NkT | ||
| k = 1.38 x10-23 J/K | |||
| 2. | What's a mole? | ||
| A mole of material X is MX grams of X, where MX = the molecular weight of X | |||
| A mole of X contains Avogadro's Number of molecules of X | |||
| NA = 6.024 x1023 | |||
| 3. | Equation of State: PV = nRT | ||
| R = 8.31 J/mol*K | |||
| 12.4. | Kinetic Theory | ||
| 1. | Assumptions | ||
| 2. | N mass m particles in a box with volume V | ||
| a. | Particle force on the walls | ||
| b. | Relation between P and average KE per particle: PV = N(2/3)KEav = N(1/3)m[v2]av | ||
| c. | Relation between T and average KE per particle: (1/2)m[v2]av = (3/2) kT | ||
| d. | Root-mean-square speed: vrms = sqrt [3kT / m] | ||