Problem Set #4 Laws of Thermodynamics 1. A sealed rigid vessel contains 2 kg of fluid that is being simultaneously heated and stirred by a propeller inside the vessel. The internal energy of the uid is initially 400 :;. The heat transfer to the fluid, 0. is 400 g, and the propeller does 50 3% of work on the uid. What is the total internal energy content of the fluid? 2. A sealed rigid vessel contains 2 kg of fluid that is being stirred by a propeller. The propeller rotates with a torque (a twisting force) 1' of 150 Newton-meters and completes 200 revolutions. Simultaneously, 100 Id of heat is lost to the surroundings. The initial internal energy is 200 3%. What is the nal total internal energy content of the uid? Hint: Work [Joules] = F d cos 9 = 1: 271: N, where N = it of revolutions 3. A generalized steam system is shown below. The system is in steady-state operation (neither heating up nor cooling down}. Assume no friction or other losses. a. How much heat is rejected by the condenser? b. What is the power capacity of this system in Megawatts [MW]