Acooling tower for an engineering process takes in air at 20 °c dry bulb with a relative humidity of 70% and discharges air at 29 °c dry bulb with a relative humidity of 95%. the air flow is recorded to be 400 m per hour at the inlet point. what is the quantity of heat energy being produced by the process and how much will it cost in top-up water alone, for an 8 hour shift, if the top-up water costs €0.20/litre. you may assume the air and humidity values are consistent during the complete 8hr shift.

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?