Question

A gas in a cylinder held at a constant pressure of $1.7\times {10}^{5}Pa$ and is cooled and compressed from $1.20m^{3}to0.8m^3$. The internal energy of the gas decreses by $1.1\times {10}^{5}J$. If the work done by the gas is $-x\times {10}^3$ J. Find $x$

Answer 1

Work done is given by:
$w=\int PdV$ ; P = constant = $P_0$
$w=\int PdV=\int P_{0}dV=P_0(V_2-V{}_1)$
$w=1.7\times {10}^5(0.8-1.2)=-0.68\times {10}^5=-68\times {10}^{3}J$
$x=68$