Temperature, Heat, and the first law of thermodynamics formulas Flashcards
Temperature (constant-volume gas thermometer)
T = (273.16K) × lim gas -> 0 (p/p3)
Conversion of Other Temps. from Kelvin temp
Celsius Temp = T - 273.15
Farenheit Temp = 9/5 Celsius temp + 32
Thermal expansion (change in L)
ΔL = LαΔT
α is the coefficient of linear expansion
Thermal expansion (change in volume)
ΔV = VβΔT
β = 3α is the coefficient of volume expansion
Heat conversions (calories, joules. british thermal units)
1 cal = 3.968 × 10 ^(-3) Btu = 4.1868 J
relationship of temperature change with heat Q
Q = C (Tf - Ti)
C is the heat capacity of the object
Heat of an object when it has mass
Q = cm (Tf - Ti)
c is the specific heat of the material
molar specific heat = 6.02 × 10^(23)
Heat transformation
Q = Lm
Work Associated with volume Change
W = ∫dW = ∫p dV [ from Vi to Vf]
First Law of Thermodynamics
ΔE int = Eint,f - Eint,i = Q - W
dEint = dQ -dW
Application of the First Law
adiabatic processes:
Q = 0, ΔEint = -W
constant-volume processes:
W = 0, ΔEint = Q
cyclical processes:
ΔEint = 0, Q = W
free expansions:
Q = W = ΔEint = 0
Conduction of Energy (Rate)
Pcond = Q/t = kA [(TH - TC)/L]
TH = higher temp
TC = lower temp
Rate of radiation energy
Prad = σεAT^4
σ = 5.6704 × 10 ^(-8) W/m^2×K^4
ε is the emissivity of the object’s surface
Stefan-Boltzmann constant
σ = 5.6704 × 10 ^(-8) W/m^2×K^4
Rate of radiation energy absor[topm
Pabs = σε AT^4(env)