Atube made of an aluminum alloy with ultimate strength u = 476 mpa has a diameter of 120 mm and a thickness of 4 mm. the tube is subjected to a constant bending moment of 2 kn·m and an internal pressure that repeatedly cycles between zero and a maximum of 15 mpa. determine: (a) the cycles that can be applied before failure nf, if the material follows the fatigue relationship a =a nf m, where a = 839 mpa and m = –0.102.

Adouble-strand no. 60 roller chain is used to transmit power between a 13-tooth driving sprocket rotating at 300 rev/min and a 52-tooth driven sprocket. a) what is the allowable horsepower of this drive? b) estimate the center-to-center distance if the chain length is 82 pitches. c) estimate the torque and bending force on the driving shaft by the chain if the actual horsepower transmitted is 30 percent less than the corrected (allowable) power.

Inspection for bearing condition will include: (clo4) a)-color b)-smell c)-size d)-none of the above

Ahe-xe mixture containing a 0.75 mole fraction of helium is used for cooling electronics in an avionics application. at a temperature of 300 k and atmospheric pressure, calculate the mass fraction of helium and the mass density, molar concentration and molecular weight of the mixture. if the cooling capacity is 10 l, what is the mass of the coolant?