12â75 the emissivity of a tungsten filament can be approximated to be 0.5 for radiation at wavelengths less than 1 mm and 0.15 for radiation at greater than 1 mm. determine the average emissivity of the filament at (a) 2000 k and (b) 3000 k. also, determine the absorptivity and reflectivity of the filament at both temperatures

Journeyman training is usually related (clo2) a)-to specific tasks b)-to cost analysis of maintenance task c)-to control process to ensure quality d)-to installation of machinery

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?

Areaction-bonded silicon nitride ceramic has a strength of 250 mpa and a fracture toughness of 3.4 mpa(m)^1/2, what is the largest-sized internal flaw that this material can support without fracturing? (use y -1 in the fracture-toughness equation.)