A 0.3-kg block is placed against a rotating hollow cylinder of inner radius = 0.7 m. The cylinder rotates around the vertical axis with a constant angular velocity of 15 rad/s. For friction to prevent the mass from sliding down the wall, what is the minimum coefficient of static friction u between the mass and the wall? %3D R

A 0.3-kg block is placed against a rotating hollow cylinder of inner radius = 0.7 m. The cylinder rotates around the vertical axis with a constant angular velocity of 15 rad/s. For friction to prevent the mass from sliding down the wall, what is the minimum coefficient of static friction u between the mass and the wall? %3D R

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 7.81P: Calculate the horizontal force P required to push the 85-lb lawn mower at constant speed. The center...

See similar textbooks

Similar questions

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.
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 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 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.
Consider the system of two blocks. Thereis no friction between block A and the tabletop. The mass of block B is5.00 kg. The pulley rotates about a frictionless axle, and the light ropedoesn’t slip on the pulley surface. The pulley has radius 0.200 m andmoment of inertia 1.30 kg . m2. If the pulley is rotating with an angularspeed of 8.00 rad/s after the block has descended 1.20 m, what is themass of block A?
A package of mass m is placed inside a drum that rotates in the verticalplane at the constant angular speed ˙ θ = 1.36 rad/s. If the package reaches the position θ = 45◦ before slipping, determine the static coefficient of friction between the package and the drum.
A cylinder of mass M and radius R is rotated in a uniform V groovewith constant angular speed ω. The coefficient of friction betweenthe cylinder and each surface is μ. What torque must be applied tothe cylinder to keep it rotating?
In a porter governor the mass of the central load is 18 kgand the mass of each ball is 2kg. the top arms (254) mm while the bottom arms are (304) mm long. The friction of the sleeve is 20 N. If the top arms make 45 deg with the axis of rotation in the equilibrium position, find the range of the speed of the governor in that position
A cube with mass of m=80N is on the inclined plane with angle of phi=20 degrees. coeficient of static friction /mu_s = 0.25 coeficient of dynamic friction /mu_k = 0.15 Determine: what is the smallest size of the force F parallel to the inclined plane, which prevents the cube in the slide? what is the smallest size of the force F, which the cube starts to move along the inclined plane up? At what value of the force F starts the cube to rise at a constant speed?
A centrifugal clutch has four shoes, each of mass 0·35 kg. When at rest, the radialclearance between the shoes and the clutch drum is 15 mm and the radius to the centre ofgravity of the shoes is 225 mm. The shoes are held on retaining springs of stiffness 10kN/m and the internal diameter of the clutch drum is 600 mm. The coefficient of frictionbetween the drum and the shoes is 0·3.Determine:(a) The speed (in rev/min) at which the clutch starts to engage. For a rotational speed of 1200 rev/min:(b) The force each shoe exerts on the drum. (c) The torque transmitted. (d) The power transmitted.
In a Porter governor, the mass of the central load is 18 kg and the mass of each ball is 2 kg. The toparms are 250 mm while the bottom arms are each 300 mm long. The friction of the sleeve is 14 N. Ifthe top arms make 45° with the axis of rotation in the equilibrium position, find the range of speed ofthe governor in that position.