2013-2-27 Basic concepts:System Classification 1+2Closed System(Control of energy (heat and work).but no mass exchange. Basic concepts:Closed System 38 19 2013-2-27 19 1 2 4 3 Mass, M Work, W heat , Q 1+2 ⇒ Closed System (Control mass): between a system and surrounding, there are exchanges of energy (heat and work), but no mass exchange. 37 Basic concepts: System Classification 38 Basic concepts: Closed System