A corroded metal gusset plate was found on a bridge. It was estimated that the original area of the plate was 750 cm2 and that approximately 2.5 kg had corroded away during use. Assuming a corrosion penetration rate of 0.5 mm/year for this metal, estimate the time since construction of the bridge. The density of the alloy is 10 g/cm3 .

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.