Consider an opaque horizontal plate that is well insulated on its back side. the irradiation on the plate is 2500 w/m2 , of which 500 w/m2 is reflected. the plate is at 227c and has an emissive power of 1200 w/m2 . air at 127c flows over the plate with a heat transfer convection coefficient of 15 w/m2 k. determine the emissivity, absorptivity, and radiosity of the plate. what is the net heat transfer rate per unit area?

Acompressor receives the shaft work to decrease the pressure of the fluid. a)- true b)- false

Slip occurs via two partial dislocations because of (a) the shorter path of the partial dislocation lines; (b) the lower energy state through partial dislocations; (c) the charge balance.

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?