Work in isobaric expansion

Problem

A gas expands isobarically at pressure $p = 1{,}0\cdot 10^5\ \text{Pa}$ from $V_1 = 0{,}10\ \text{m}^3$ to $V_2 = 0{,}30\ \text{m}^3$. Calculate the work done by the gas.

Solution

Work at constant pressure. When the pressure does not change: $L = p\,\Delta V = p\,(V_2 - V_1)$

Numerical substitution. $L = 1{,}0\cdot 10^5\cdot(0{,}30 - 0{,}10) = 1{,}0\cdot 10^5\cdot 0{,}20$

$\ev{L = 2{,}0\cdot 10^4\ \text{J}}$

The work is positive: as the gas expands it does work on the surroundings.

Links

Topics: Thermodynamics Concepts: Thermodynamic processes Objects: Ideal gas