Explain the work of an architectural engineer

What is the major difference between thermoplastics and thermosetting plastics from the polymerization structure point of view?

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?

An ammonia compressor has a 5% clearance volume and displacement rate of 80 l/s and pumps against a condensing temperature of 40°c. for two different temperatures of -10°c and 10°c, compute the mass flow rate of refrigerant assuming the clearance volumetric efficiency applies. discharge specific volume corresponding to-10°c and 10°c are 112.5 l/kg and 95 l/kg, respectively.