Answer:
The positive sign indicates that work is done by the gas.
Explanation:
Let consider that gas inside the cylinder behaves ideally and process is isothermal, so that change in internal energy can be neglected. The engine cylinder is modelled after the First Law of Thermodynamics:
[tex]W + P\cdot(V_{in}-V_{out}) = 0[/tex]
[tex]W = P\cdot (V_{out}-V_{in})[/tex]
[tex]W = P\cdot A\cdot \Delta x[/tex]
[tex]W = (7.5\times 10^{5}\,Pa)\cdot (0.01\,m^{2})\cdot (0.04\,m)[/tex]
[tex]W = 300\,kPa[/tex]
The positive sign indicates that work is done by the gas.
