PROBLEM 5: The upper block is attached to the ground as shown in the figure by a short rope. The coefficient of friction between the blocks is 0.25 while the angle of friction between the lower block and the horizontal ground is 30°. (a) Determine the tension in the rope, in N, when the lower block is about to move. (b) Determine friction force, in N, under the 900 N block when it is about to move. (c) Determine the horizontal force P, in N, required to initiate motion. 300 N P 900 N 30°

PROBLEM 5: The upper block is attached to the ground as shown in the figure by a short rope. The coefficient of friction between the blocks is 0.25 while the angle of friction between the lower block and the horizontal ground is 30°. (a) Determine the tension in the rope, in N, when the lower block is about to move. (b) Determine friction force, in N, under the 900 N block when it is about to move. (c) Determine the horizontal force P, in N, required to initiate motion. 300 N P 900 N 30°

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 7.8P: The brake pads at C and D are pressed against the cylinder by the spring BF. The coefficient of...

See similar textbooks

Similar questions

A wedge is used to prop up the 6000-lb block of marble. The wedge angle is =30, and the angle of static friction is s=12 between all contact surfaces. Determine the smallest force P that would prevent the wedge from sliding out.
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.
Two identical chairs, each weighing 14 lb, are stacked as shown. The center of gravity of each chair is denoted by G. The coefficient of static friction is 0.2 at B (the contact point between the chairs) and 0.35 at A, C, and D. Determine the smallest force P that would cause sliding.
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.
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.
Draw the FBD of the entire frame, assuming that friction and the weights of the members are negligible. How many unknowns appear on this FBD?
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 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.
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 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 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.
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.