A load of 20 kN is supported by a conical pivot. The angle of cone is 120° and intensity of pressure is not to exceed 3.5 bar. The external radius is 3 times the internal radius. Find the diameter of the bearing surface. If coefficient of friction is 0.06 and speed of the shaft is 120 r.p.m, find the power absorbed by friction.

2. A thin flywheel rim 1.2m in diameter,is made of cast iron density 7.21 g/cm³.Find the speed in rpm at which the stress due to centrifugal force is 15MPa.

An open belt 100 mm wide connects two pulleys mounted on parallel shafts with their centres 2.4 m apart. The diameter of the larger pulley is 450 mm and that of the smaller pulley 300 mm. The coefficient of friction between the belt and the pulley is 0.3 and the maximum stress in the belt is limited to 14 N/mm width. If the larger pulley rotates at 120 r.p.m., find the maximum power that can be transmitted. [Ans. 2.39 kW]

Please solve this question in handwriting. Again please in writing.

Q3) The screw, as shown is operated by a torque applied to the lower end. The nut is loaded and prevented from turning by guides. Assume friction in the ball bearing to be negligible. The screw is a triple-start trapezoidal thread. The outside diameter of the screw is 48 mm and the pitch is 8 mm. The coefficient of friction of the threads is 0.15. For trapezoidal threads, 2 B=30°) Find: 1. Load which can be raised by a torque of 40 N-m; and W 8 W.C.n Pb G.d ndin 2. Average bearing pressure between the screw and nut thread surface. T; = 23 x 1, XW [ (R₁) ³ - (R₂)³] (R₁)²-(R₂)²] 8 (Assuming uniform wear conditions) =H₁XWXR TRANSPRAR PARAhabinoin crime (Assuming uniform pressure conditions) *********** ke 50 mm

4.As shown in the figure, a square threaded screw is used in a vise to exert a pressure of 2 tons. If the screw is double-threaded and has a pitch of 0.25 m and a mean radius of 1.5 inch, determine the torque that must be applied at B to create this pressure. Assume the coefficient of friction to be 0.15. P

Question 4 A pulley is driven by a flat belt, the angle of lap being 120°. The belt is 100 mm wide by 6 mm thick and density is 1000 kg/m. If the coefficient of friction is 0.3 and the maximum stress in the belt is not to exceed 1.5 MPa. Calculate: 4.1. 4.2. the speed of the belt in m/s using the information related to driving pulley. the centrifugal tension and the tension on the first tight side of the belt T1. the greatest power the belt can transmit. 4.3

Q2) A single block brake, as shown in figure, has the drum diameter 250 mm. The angle of contact is 90° and the coefficient of friction between the drum and the lining is 0.35. The other dimensions are as follows: a = 200 mm, 1 = 400 mm and b = 100 mm. If the torque transmitted by the brake is 70 N-m, find the force F required to operate the brake CTTTTTTX

An overhang shaft carry a 900mm diameter pulley, whose center is 250mm from the center of nearest bearing. The weight of the pulley is 600N and the angle of lap is 180°.The pulley is driven by motor horizontally to right it, if the permissible tension in the belt is 2650N and the coefficient of friction between the belt and the pulley surface is 0.3, estimate the diameter of the shaft. Note, Neglect centrifugal tension and assume permissible tensile and shear stresses in the shaft as 84MPA and 68MPa respectively.

A 150lb man stands on a 60lb bar to which a cable is fixed at B. The cable passes over two fixed pegs with coefficients of friction indicated.  Assume that the arrangement of the pegs permits the cable to contact each peg over a total angle of 90-degrees (90-degrees per peg).  Assume that the normal force exerted by the man on the bar acts downward through A.  Find the largest force the man can exert on the cable and maintain the bar horizontal.