Water is the working fluid in an ideal Rankine cycle with reheat. Superheated vapor enters the turbine at 12 MPa, 480°C, and the condenser pressure is 8 kPa. Steam expands through the first-stage turbine to 1.2 MPa and then is reheated to 480°C. Assume the pump and each turbine stage has an isentropic efficiency of 85% and 92%, respectively. Determine the thermal efficiency as a percent (do not include the % symbol in your answer)

Tom is having a problem with his washing machine. he notices that the machine vibrates violently at a frequency of 1500 rpm due to an unknown rotating unbalance. the machine is mounted on 4 springs each having a stiffness of 10 kn/m. tom wishes to add an undamped vibration absorber attached by a spring under the machine the machine working frequency ranges between 800 rpm to 2000 rpm and its total mass while loaded is assumed to be 80 kg a) what should be the mass of the absorber added to the machine so that the natural frequency falls outside the working range? b) after a first trial of an absorber using a mass of 35 kg, the amplitude of the oscillation was found to be 10 cm. what is the value of the rotating unbalance? c) using me-3.5 kg. m, find the optimal absorber (by minimizing its mass). what would be the amplitude of the oscillation of the absorber?