the system is compressed, then the work is positive and the internal energy of the system increases. Conversely, if the system expands, it does work on the surroundings and the int...
In chemistry we are interested in internal energy of the system. So anything that increases the internal energy of the system is taken as positive. Compression is the work done on ...
But in Physics we are interested in work done by the system as we have to extract work from machine. So work done by the system is positive i.e expansion is taken as negative.
Suresh khokhar Best Answer
all compression work is positive. an expansion work is negative.