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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). |