Aspeed reducer has 20 full-depth teeth and consists of a 20-tooth steel spur pinion driving a 50-tooth cast-iron gear. the horsepower transmitted is 12 at a pinion speed of 1200 rev/min for a diametral pitch of 8 teeth/in and a face width of 1.5 in, find the contact stress

Fluids at rest possess no flow energy. a)- true b)- false

Apipe with an outside diameter of 15 cm is exposed to an ambient air and surrounding temperature of -20°c. the pipe has an outer surface temperature of 65°c and an emissivity of 0.85. if the rate of heat loss from the pipe surface is 0.95 kw per meter of length, the external convective heat transfer coefficient (h) is: (a) 12.5 w/m"k (b) 18.6 w/mk (c) 23.7 w/mk (d) 27.9 w/mk (e) 33.5 w/mk

Compute the pressure drop of 30°c air flowing with a mean velocity of 8 m/s in a circular sheet-metal duct 300 mm in diameter and 15 m long. use a friction factor, f 0.02, and pair = 1.1644 kg/m a. 37.26 pa b. 25.27 pa n c. 29.34 pa d. 30.52 pa