Acompressor requiring 89.5 kw, is to run at about 250 rpm. the drive is by v-belts from an electric motor running at 750 rpm. the diameter of the pulley on the compressor shaft must not be greater than 1 m while the centre distance between the pulleys is limited to 1.75 m. the belt speed should not exceed 1600 m/min. determine the number of v-belts required to transmit the power if each belt has a cross sectional area of 3.75 cm' and weighs 0.00981 n/cm and has an allowable tensile stress of 245.2 n/cm. the groove angle of the pulley is 35'. the co-efficient of friction between the belt and the pulley is 0.25. calculate also the length required of each belt.

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?