Block A lies on the top of block C and is connected with block B by a massless unstretchable string passing over a massless and frictionless pulley. Block B is also in contact with the block C (see picture). Masses of blocks A and B are the same MĄ =mg =m and the coefficient of friction between each of them and block C is µ. (a) What should be a constant acceleration a in horizontal direction from the left to the right of the whole system in order that blocks A and B do not move with respect to the block C? (b) What will be an acceleration of the blocks A and B if the whole system initially is at rest and then blocks A and B are released and start moving? (Hint: in both cases start with free body diagrams for blocks A and B)

Block A lies on the top of block C and is connected with block B by a massless unstretchable string passing over a massless and frictionless pulley. Block B is also in contact with the block C (see picture). Masses of blocks A and B are the same MĄ =mg =m and the coefficient of friction between each of them and block C is µ. (a) What should be a constant acceleration a in horizontal direction from the left to the right of the whole system in order that blocks A and B do not move with respect to the block C? (b) What will be an acceleration of the blocks A and B if the whole system initially is at rest and then blocks A and B are released and start moving? (Hint: in both cases start with free body diagrams for blocks A and B)

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 7.49P

See similar textbooks

Similar questions

The block of weight W is pulled by the force P inclined at the angle to the horizontal. Find the smallest force P and the corresponding angle that would cause impending sliding of the block. The angle of static friction between the block and the ground is s.
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.
Calculate the horizontal force P required to push the 85-lb lawn mower at constant speed. The center of gravity of the mower is at G, and the coefficients of rolling resistance are 0.12 for the front wheels and 0.18 for the rear wheels.
Find the smallest distance d for which the hook will remain at rest when acted on by the force P. Neglect the weight of the hook, and assume that the vertical wall is frictionless.
The contact surface between the 36-lb block and 20-lb homogenous cylinder is frictionless. Can the system be in static equilibrium 0n the rough inclined plane?
The 40-lb spool is suspended from the hanger GA and rests against a vertical wall. The center of gravity of the spool is at G and the weight of the hanger is negligible. The wire wound around the hub of the spool is extracted by pulling its end with the force P. If the coefficient of static friction between the spool and the wall is 0.25, determine the smallest P that will extract the wire.
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 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 brake pads at C and D are pressed against the cylinder by the spring BF. The coefficient of static friction between each pad and the cylinder is 0.15. Find the smallest tension in the spring that would prevent the cylinder from rotating when the clockwise couple M=2200lbin. is applied. Neglect the weights of the members.
Determine the smallest horizontal force P that must be applied to block B to cause impending motion. The angles of static friction are 15 between the blocks and 30 between the blocks and the ground.
The force P applied to the brake handle enables the band brake to reduce the angular speed of a rotating drum. If the tensile strength of the band is 3800 lb, find the maximum safe value of P and the corresponding braking torque acting on the drum. Assume that the drum is rotating clockwise.
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.