Category: Part 2: Thermodynamics
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Problem 2.131 — Stefan-Boltzmann Law: Radiation Power
Problem Statement Solve the work-energy problem: Solve the work-energy problem: A black body of area $A=0.01\ \text{m}^2$ is at $T=1000\ \text{K}$. Find the total radiated power. Stefan-Boltzmann law: $P = \sigma_{SB} A T^4$, where $\sigma_{SB} = 5.67\times10^{-8}\ \text{W/m}^2\text{K}^4$. $$P = 5.67\times10^{-8}\times0.01\times(1000)^4 = 5.67\tim Given Information $\sigma_{SB} = 5.67\times10^{-8}\ \text{W/m}^2\text{K}$ Physical Concepts & Formulas This problem…
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Problem 2.128 — Internal Pressure of Real Gas
Problem Statement Solve the fluid mechanics problem: Solve the fluid mechanics problem: Define the internal pressure of a real gas and calculate it for nitrogen at $T=300\ \text{K}$, $V=1\ \text{L}$/mol. ($a=0.136\ \text{J·m}^3/\text{mol}^2$) Internal pressure: $\pi_{int} = (\partial U/\partial V)_T$. From the thermodynamic identity: $(\partial U/\par Given Information See problem statement for all given quantities. Physical…
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Problem 2.129 — Thermodynamic Temperature Scale
Problem Statement Solve the thermodynamics problem: Solve the thermodynamics problem: Show that the thermodynamic (Kelvin) temperature scale defined by the Carnot efficiency $\eta = 1 – T_2/T_1$ is independent of the working substance. Consider two Carnot engines in series: engine A operates between $T_1$ and $T$, engine B between $T$ and $T_2$. The Given Information…
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Problem 2.126 — Entropy Change: Adiabatic Irreversible Expansion
Problem Statement Solve the thermodynamics problem: Solve the thermodynamics problem: One mole of ideal gas (diatomic) is adiabatically and irreversibly expanded against zero external pressure (free expansion) from $V_1=5\ \text{L}$ to $V_2=20\ \text{L}$. Find $\Delta T$, $\Delta U$, $\Delta S$. $\Delta T$: In free expansion against zero pressure, $W Given Information See problem statement for…
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Problem 2.127 — Polytropic Index from $pV$ Data
Problem Statement A gas undergoes a process where $p_1=1\ \text{atm}$, $V_1=10\ \text{L}$ and $p_2=4\ \text{atm}$, $V_2=4\ \text{L}$. Find the polytropic index $n$. Given Information See problem statement for all given quantities. Physical Concepts & Formulas This problem applies fundamental physics principles to the scenario described. The solution requires identifying the relevant conservation laws and equations…
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Problem 2.124 — Adiabatic Compressibility vs Isothermal
Problem Statement Solve the thermodynamics problem: Solve the thermodynamics problem: Show that $\kappa_S = \kappa_T/\gamma$, where $\kappa_S$ and $\kappa_T$ are adiabatic and isothermal compressibilities. $\kappa_T = -\frac{1}{V}(\partial V/\partial p)_T$ and $\kappa_S = -\frac{1}{V}(\partial V/\partial p)_S$. From $pV^\gamma = \text{const}$ (adiaba Given Information See problem statement for all given quantities. Physical Concepts & Formulas This problem…
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Problem 2.125 — Work Done in a Throttling Process
Problem Statement Solve the work-energy problem: Solve the work-energy problem: Show that the enthalpy is conserved in a throttling (Joule-Thomson) process. In a throttling process, gas flows steadily through a porous plug or constriction. Consider a unit mass flowing from high-pressure side (pressure $p_1$, specific volume $v_1$) to low-pressure Given Information See problem statement for…
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Problem 2.123 — Gruneisen Parameter
Problem Statement Define the Gruneisen parameter $\Gamma = V(\partial p/\partial U)_V$ and show it relates thermal pressure to internal energy in solids. Given Information See problem statement for all given quantities. Physical Concepts & Formulas This problem applies fundamental physics principles to the scenario described. The solution requires identifying the relevant conservation laws and equations…
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Problem 2.121 — Work Done by Van der Waals Gas in Isothermal Expansion
Problem Statement Solve the thermodynamics problem: Solve the work-energy problem: One mole of a van der Waals gas expands isothermally at $T=300\ \text{K}$ from $V_1=1.0\ \text{L}$ to $V_2=10\ \text{L}$. The constants are $a=0.136\ \text{J·m}^3/\text{mol}^2$, $b=38.5\ \text{cm}^3/\text{mol}$. Find the work done and compare with the ideal gas value. Given Information See problem statement for all given…
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Problem 2.122 — Heat Capacity at Constant Pressure: General Formula
Problem Statement Solve the thermodynamics problem: Solve the thermodynamics problem: Show that for any substance: $C_p – C_v = -T\frac{(\partial p/\partial T)_V^2}{(\partial p/\partial V)_T}$. Start from $C_p – C_v = T(\partial p/\partial T)_V(\partial V/\partial T)_p$. Using the triple product rule: $(\partial V/\partial T)_p = -(\partial p/\partia Given Information See problem statement for all given quantities.…