2. A pulley with a diameter of 4 in. can rotate about a fixed shaft with a diameter of 2 in. The coefficient of static friction between the pulley and shaft is 0.20. Determine (a) the smallest vertical force P required to start raising a 500-lb load, (b) the smallest vertical force P required to hold the load, (c) the smallest horizontal force P required to start raising the same load.

2. A pulley with a diameter of 4 in. can rotate about a fixed shaft with a diameter of 2 in. The coefficient of static friction between the pulley and shaft is 0.20. Determine (a) the smallest vertical force P required to start raising a 500-lb load, (b) the smallest vertical force P required to hold the load, (c) the smallest horizontal force P required to start raising the same load.

International Edition---engineering Mechanics: Statics, 4th Edition

4th Edition

ISBN:9781305501607

Author:Andrew Pytel And Jaan Kiusalaas

Publisher:Andrew Pytel And Jaan Kiusalaas

Chapter7: Dry Friction

Section: Chapter Questions

Problem 7.63P: The leather rein used to fasten the horse to the hitching rail weighs 3.5 oz per foot. The...

See similar textbooks

Similar questions

A uniform plank is supported by a fixed support at A and a drum at B that rotates clockwise. The coefficients of static and kinetic friction for the two points of contact are as shown. Determine whether the plank moves from the position shown if (a) the plank is placed in position before the drum is set in motion; and (b) the plank is first placed on the support at A and then lowered onto the drum, which is already rotating.
The coeffient of static friction between the uniform bar AB of weight W and the ground is 0.45. Find the smallest angle and the corresponding force P that would initiate simultaneous tipping and sliding of the bar.
The cone clutch transmits the torque C through a conical friction surface with cone angle . The inner and outer radii of the friction surface are a and b, respectively. The left half of the clutch is keyed to the shaft, and the right half drives a machine (not shown) through a gear attached to its outer rim. Assuming uniform pressure on the friction surface, show that the maximum torque that can be transmitted by the clutch is
The square-threaded screw with a pitch of 10 mm and a mean radius of 18 mm drives a gear that has a mean radius of 75 mm. The static and kinetic coefficients of friction between the gear and the screw are 0.12 and 0.06, respectively. The input torque applied to the screw is C0=10Nm. Assuming constant speed operation, determine the output torque C1 acting on the gear.
Determine the smallest coefficient of static friction at A for which the system shown is self-locking (can support the force P of any magnitude). Neglect the weight of bar AB.
The figure shows a steel bar being processed by a rolling mill. Given that P=80kN and r =0.016, determine the force F required to advance the bar at a constant speed.
The leather rein used to fasten the horse to the hitching rail weighs 3.5 oz per foot. The coefficient of static friction between the rail and the rein is 0.6. If a 34-lb force acting on the bridle is sufficient to restrain the horse, determine the smallest safe length L for the free end of the rein.
A 1.1-kg disk A is placed on the inclined surface. The coefficient of static friction between the disk and the surface is 0.35. Is the disk in equilibrium if P=5.5N and =30?
The blocks A and B of weights WA and WB are joined by a rope that passes over the fixed peg C. The coefficients of static friction are =0.2 between block A and the inclined plane, and =0.25 between the rope and the peg. Determine the range of Wb/WA for which the system will be in equilibrium.
A pulley with a diameter of 4 in. can rotate about a fixed shaft with a diameter of 2 in. The coefficient of static friction between the pulley and shaft is 0.20. Determine; a. the smallest vertical force P required to start raising a 500-lb load. b. thesmallest vertical force P required to hold the load. c. the smallest horizontal force P required to start raising the same load.
Problem 4. A.) If the uniform concrete block has a mass of 500 kg, determine the smallest horizontal force P needed to movethe wedge to the left. The coefficient of static friction between the wedge and the concrete and the wedge and the floor is 0.3. The coefficient of static friction between the concrete and floor is 0.5.ANSWER: P=1797.52; N=1.80kNB.)Refer to problem number 4. Calculate the followinga.) the angle of friction between the wedge and the concrete and the wedge and the floor.Answer: ?????? ??? ????????= ?????? ??? ?????= 16.7ob.) the coefficient of static friction between the concrete and floor.Answer: ????????? ??? ?????= 263.56o
A 20 kg block is held in place on an incline plane as shown by a rope that passesover a frictionless pulley at B and then over a fixed cylinder at C where thecoefficient between the rope and the fixed cylinder is 0.2. Given an angle ofincline, A = 25°, if a force of P = 200 V is applied to the end of the rope,(a) Will the block move if the coefficient of static friction between the block and theinclined surface is M, = 0.56?(b)If impending motion exists, will the block tip or slip?