Question

Do anyone have any strategies, guides, videos, or anything relating to identifying unsteady/steady and open/closed systems in thermodynamic problems? I am struggling to identify these features when doing problems, and the text does not explicitly state a process on determining these.

Answer 1

Unsteady state itself gives that it is not a stable in thermodynamic problems the state of study of unsteady or steady is depends on the property of Temperature .

in a given problem to identify the state just observe the temperature wether it changes with time or not. If temperature changes with time in the body then the state is unsteady if don't change with time it's a steady .

For a given system we have to tell open or closed system it depends on two things 1.energy transfer 2.mass transfer

If both energy and mass transfers takes place it is a open system . If only energy transfer takes place is a closed system.

Example : in a piston cylinder arrangements with valves close then energy transfer only takes place it is a closed system.

If valves are open both energy and mass transfers takes place so it is a open system.

So finally my conclusion is to find whether the state is steady /unsteady observe Temperature changes with time

For open /closed system observe whether mass and energy transfer takes place or not. Then you get answers easily.