2 A ladder 5 m long and weighing 260 N is placed against a vertical wall at an inclination of 30 ^ 0 with wall. A wan weighing 780 N climbs the ladder. When he is at a distance of 1.64 m along the ladder from lower all contact surfaces? end, the ladder slips. What is the coefficient of friction assuming it to be same for

2 A ladder 5 m long and weighing 260 N is placed against a vertical wall at an inclination of 30 ^ 0 with wall. A wan weighing 780 N climbs the ladder. When he is at a distance of 1.64 m along the ladder from lower all contact surfaces? end, the ladder slips. What is the coefficient of friction assuming it to be same for

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 7.50P: The block of weight W is pulled by the force P inclined at the angle to the horizontal. Find the...

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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.
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.
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.
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?
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 test specimen AB is placed in the grip of a tension-testing machine and secured with a wedge. The coefficient of static friction at both surfaces of the specimen is s. If the wedge angle is =18, determine the smallest s for which the grip is self-locking (no slipping takes place regardless of the magnitude of the force P). Neglect the weight of the wedge.
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.
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 25-kg ladder, 4 m long, rests on a rough floor and against a vertical wall. The ladder makes an angle of 350 with the horizontal as shown. It starts to slip when a man weighing 75 kg has climbed halfway up. If f = 0.20 at the wall, find the coefficient of friction (µf) at the floor.
A homogeneous ladder 20m long weighing 50 N is leaning against a wall makes an angle of 15 degrees with the wall. Assuming that the coefficient of friction at all contact surfaces is 0.20. What horizontal force (F) acting on the lower third point of the ladder will cause it to slip outward?
A ladder of length 5 m is resting against a smooth wall, its point of contact being just below a first floor window. The bottom of the ladder rests on the ground and the coefficient of friction between the ladder and the ground is 0.3. A person of mass 75 kg climbs the ladder, which has a mass of 4 kg. The bottom of the ladder is at the point of slipping, outward from the wall, just as the person reaches the mid-point of the ladder’s length. Draw a free body diagram of the ladder and calculate the maximum frictional force opposing the slipping motion. In addition, determine the angle of inclination (θ) of the ladder, when the person is at the mid-point and the ladder is on the verge of slipping.