The First Law of Thermodynamics is an energy conservation of law. Mathematically, it can be presented by the following two equations:

a$)E_{12}=Q_{12}-W_{12}$

b$),E_{12}=E_{in}-E_{\text{o}\text{u}\text{t}}$

Answer the following questions:

i$)$ Can you use both equations for any thermodyamic system for an interval of time? Why?

ii$)$ There are three different ways to transfer energy into and out from any thermodynamic system. What are they?