a cylindrical 4340 steel bar is subjected to reversed rotating–bending stress cycling, which yielded the test results presented in animated figure 8.21. if the maximum applied load is 5,000 n, compute the minimum allowable bar diameter to ensure that fatigue failure will not occur. assume a factor of safety of 2.25 and that the distance between loadbearing points is 55.0 mm.

An electrical motor raises a 50kg load at a construct velencity .calculate the power of the motor, if it takes 40sec to raise the load through a height of 24m(take g =9.8n/g)

During a steady flow process, the change of energy with respect to time is zero. 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