Compression and Work, Heat [ENDORSED]

[Raj Susarla 3I]

Just wondering if someone could explain exactly why compression increases the internal energy of the system, and how work and heat are both affected when compression occurs.

[vsyacoubian2A]

Compression means work is being done on the system. Since the system is not exerting energy to do work and is getting free work, the value for work is positive. In the formula U=q+w, w is positive. If q is constant, you can say that the system gains energy. Work is affected by compression.