(b): The mechanical work will be stored in the system as internal energy, thus ΔU > 0, also as the system is thermally insulated, thus q = 0. Mechanical stirring is done on the system so, w > 0.
(b): The mechanical work will be stored in the system as internal energy, thus ΔU > 0, also as the system is thermally insulated, thus q = 0. Mechanical stirring is done on the system so, w > 0.