Aline shaft rotating at 200 r. p.m. is to transmit 20 kw. the allowable shear stress for the material of the shaft is 42 mpa. if the shaft carries a central load of 900 n and is simply supported between bearing 3 metre apart, determine the diameter of the shaft. the maximum tensile or compressive stress is not to exceed 56 mpa.

Consider a 1.2 meter high and 2 meter wide glass window whose thickness is 6 mm and thermal conductivity is 0.78 w/m °c. the room temperature is maintained at 24 °c, while the outdoor temperature is -5 °c. the convective heat transfer coefficients on the inner and outer surfaces of the window are 10 w/m2 °c and 25 w/m2 °c respectively. (a) draw the thermal resistance network, etermine the steady rate of heat transfer t e glass window (c) determine the temperature of the inner surface of the window