Q.1) A 120 lb. block is raised by a massless screw-activated wedge as shown below. The single-threaded screw has a mean radius of 0.5 inch and advances 0.2 inch for each complete turn. The coefficient of kinetic friction for the screw threads is 0.35, and the coefficient of kinetic friction for all contact surfaces of the block and the wedge is 0.4. Calculate the moment M which must be applied to the handle of the screw to raise the block at a constant speed.

A uniform ladder 5 m long and weighing 80N rests against on a vertical wall at B and one end at A (on the ground). The angle of friction at all contact surfaces is 21.8°. Find the smallest angle 0 at which the ladder can be inclined with the horizontal before it is on its verge of slipping.

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Please solve this question in handwritting. Again in handwriting

The following lead screw and saddle arrangement is used to lift aload of 550 kg.  The square thread has a pitch of 3 mm and a diameter of 15 mm. The coefficient of friction is 0.2. Calculate the torque required to rotate the screw on raising and lowering.

High-strength bolts are used in the construction of many steel structures. For a 1-in.- nominal-diameter bolt, the required minimum bolt tension is 51 kips. Assuming the coefficient of friction to be 0.30, determine the required couple that should be applied to the bolt and nut. The mean diameter of the thread is 0.94 in., and the lead is 0.125 in. Neglect friction between the nut and washer, and assume the bolt to be square-threaded. You must show a free body diagram of your block and incline analysis of the bolt and nut, and clearly indicate your force triangle, if any.

4.) A flat belt makes contact with an 16 in. diameter pulley through half its circumference. If the coefficient of friction is 0.45 , and a torque of300ft−bsis to be transmitted, calculate the belt tensions. (please type answer not write by hend)

An arrangement of three boxes is shown in figure below. Box A weighs 25 N and rests on an inclined plane, while box B weighs 50 N and rests on a horizontal plane. The coefficient of friction between box A and the inclined plane is 0.3, and between box B and the horizontal plane is 0.4. The pulleys are all frictionless. Determine the range of weight of box C for which no motion will occur. Consider both sliding and tipping of boxes A and B. 0.6 m 0.75 m 25 N 5 A 4 C pome 0.8 m 0.6 m 50 N B 1.2 m

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.

draw free body diagram and A and B please. picture is pretty clear! Block is labeled A (under A is 25 degrees) above is 45 degrees and F pulling down is 50 degrees