QUESTION

1. Neglecting spoke effect, calculate the energy stored in the rim of a flywheel made of cast iron 24 in. in diameter, having a rim 5 inches wide by 4 inches deep when running at 1000 rpm. The internal radius of the rim is 8 inches. Note density of the material is 450 lb/ft3.

A.40122.28 ft-lb

B.38614.21 ft-lb

C.58234.36 ft-lb

D.50165.32 ft-lb

2.A wet, steel-backed asbestos clutch with hardened steel plates is being designed to transmit 33 N-m. The coefficient of friction is 0.12. Slip will occur at 300% of the rated torque. The maximum and minimum friction surface diameters are 115mm and 65mm respectively. The contact pressure is 700kPa. How many plates are needed?

A.4

B.6

C.3

D.5

3Find the root area of a 1inch bolt. which has 8V threads per inch

A.0.345 sq in

B.0.785 sq in

C.0.482 sq in

D.0.314 sq in

4,A large hangar door is required to be stopped at the end of its travel by a constant force snubber. The door weighs 10000 lbs and its speed is 1 ft/s when it strikes the snubber. What constant force is required by the snubber to stop the door within a distance of 1ft.

A.310.56lbs

B.301.65lbs

C.155.28lbs

D.128.55lbs

5. A heavy duty sleeve bearing is used with good ventilation. The bearing has a diameter of 2in and a length of 4in. The load on the bearing is 2200lb. A shaft rotates 200 rpm in the bearing. Find the heat radiating capacity. The coefficient of friction is 0.02

A.0.7404 BTU/min sq in

B.0.8765 BTU/min sq in

C.0.7654 Btu/min sq in

D.0.8043 Btu/min sq in

Public Answer

XCZVBV The First Answerer