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phyx eqns Thermal
| Question | Answer |
|---|---|
| Heat Transfer | Q = mcΔT c= specific heat |
| Phase Change | Q = mL L= latent heat ( fusion or vaporization) |
| Linear Expansion | Δl = α lo ΔT α = coefficient of linear expansion lo = original length |
| Volume Expansion | ΔV = β Vo ΔT β = Coefficient of volume Vo = original volume |
| Rate of Heat Transfer | H = Q/t or H = (k A ΔT) / L k = thermal conductivity A = Cross sectional area L = Distance Between ends |
| Ideal Gas Law | PV= nRT P = pressure V= Volume n= number of moles R= Universal Gas Constant T = Temperature |
| Average Molecular Kinetic Energy | K = 3/2 k T k = Boltzman's Constant |
| Root-mean-squared velocity | v rms = √(3 k T / m) |
| 0th Law of Thermodynamics | When A & B are in equilibrium with C. A & B are in Equilibrium with each other. |
| 1st law of Thermodynamics | ΔU = ΔQ + W U= Internal Energy Q = Heat Transferred to a System W= Work done on the gas ( if work done by the gas it is negative) |
| Work done by or on a gas | W = -PΔV or W = PΔV |
| Change in internal energy | ΔU = 3/2 NkΔT |
| Efficiency | e = W/ QH W = Output QH = Input |
| Heat Input | QH = W + QL QL = Heat that flows out |
| Ideal Efficiency | e ideal = TH - TL / TH TH = High Temp TL = Low Temp |
| Change in Entropy | ΔS = Q/T Q= Heat added |
| 2nd Law of Thermodynamics | The total entropy of any system plus that of its environment increases as a result of any natural process ΔS > 0 ΔS = ΔSs + ΔS env |
| 3rd Law of Thermodynamics | The entropy of a pure perfect crystal is zero (0) at zero Kelvin (0° K). |