Aspring-damper system is designed to support an electric motor which has a total mass of 20 kg and an unknown rotating imbalance. in free vibration, a displacement of 16 mm is damped to 1 mm in two cycles. determine the required spring stiffness so that only 20% of the vertical component of the unbalanced force is transmitted to the ground when the motor is running at 1,200 rpm, assuming the damping ratio remains constant.

For the closed feedwater heater below, feedwater enters state 3 at a pressure of 2000 psia and temperature of 420 °f at a rate of ix10 ibhr. the feedwat extracted steam enters state 1 at a pressure of 1000 psia and enthalpy of 1500 btu/lbm. the extracted er leaves at an enthalpy of 528.7 btu/lbm steam leaves as a saturated liquid. (16) a) determine the mass flow rate of the extraction steam used to heat the feedwater (10) b) determine the terminal temperature difference of the closed feedwater heater