Which Basically States that Total change Energy Bar System is equal to the change in Internal Angier System plus Pv Work Done so with this Circle is Our System and all these Malts are famil tou Circle. The change in Energy is equal to the Changing all the potential Energies And Conn etic Energydata System and the work done or the work Done by these molecules on the Surrounding Molecules in Expanding or Compressing this System here. So when there is a Constant volume, lots look our equation this guy goes to zero because at Constant volume. What Happens to change in Pressure. Well, it Zero so Change and Energy Is simply change in Internal Energy. So there is a Transfert Energy into a system.