A cast iron flywheel with a mean diameter of 36

33. A cast iron flywheel with a mean diameter of 36 inches changes speed from 300 rpm to 280 while it gives
up 8000 ft-lb energy. What is the coefficient of fluctuation?
A. 0.069 B. 0.015 C. 0.082 D. 0.020
34. Two short shafts having identical diameters of 38.1 mm and rotating at 400 rpm are connected by a flange
coupling having 4 bolts with 100 mm bolt circle. The design shearing stress of the bolts is 12 N/mm 2 and
design compressive stress of the flange is 15 N/mm 2 . What is the power transmitted by the short shaft in
KW?
35. Two short shafts having identical diameters of 38.1 mm and rotating at 400 rpm are connected by a flange
coupling having 4 bolts with 100 mm bolt circle. The design shearing stress of the bolts is 12 N/mm
2
and
design compressive stress of the flange is 15 N/mm 2 . What is the diameter of bolt should be used?
36. Two short shafts having identical diameters of 38.1 mm and rotating at 400 rpm are connected by a flange
coupling having 4 bolts with 100 mm bolt circle. The design shearing stress of the bolts is 12 N/mm 2 and
design compressive stress of the flange is 15 N/mm 2 . How thick should the flange be?
37. A flange coupling is to be designed, using 25 mm diameter bolts at a distance of 152 mm from the center of
the shaft. Allowable shearing stress on the bolt is 103 Mpa. If the shaft is to transmit 5,800 hp at a speed
of 1,200 rpm, how many bolts are needed in the connection?
A. 2 B. 3 C. 4 D. 5
38. A flange bolt coupling consists of eight steel 20 mm diameter steel bolts spaced evenly around a bolt circle
300 mm in diameter. If the coupling is subjected to a torque of 15.1 KN-m, determine the maximum
shearing stress in the bolts.
39. A pulley is keyed to a 2 and ½ inches diameter shaft by a 5/8 in x 7/16 in x 3 in flat key. The shaft rotates at
50 rpm. The allowable shearing stress for the key is 22 ksi. The allowable compressive stress for the key,
hub and shaft are 66 ksi, 59 ksi and 72 ksi, respectively. Determine the maximum torque the pulley can
safely deliver.