As shown in Figure below, a flexible belt placed around a rotating drum of 120-mm radius acts as a brake when the arm ABCD is pulled down by the force P. The coefficient of kinetic friction between the belt and the drum is 0.20 determine the force P that would result in a braking torque of 12,000-N.mm, assuming that the drum is rotating counterclockwise. Neglect the weight of the brake arm. 60° 60 | B 60 - 120 – 60 mm mm 120 mm

As shown in Figure below, a flexible belt placed around a rotating drum of 120-mm radius acts as a brake when the arm ABCD is pulled down by the force P. The coefficient of kinetic friction between the belt and the drum is 0.20 determine the force P that would result in a braking torque of 12,000-N.mm, assuming that the drum is rotating counterclockwise. Neglect the weight of the brake arm. 60° 60 | B 60 - 120 – 60 mm mm 120 mm

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

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.
The 10 N cylinder moves in a friction tube. Spring constants are k1 = 150 N / m and k2 = 200 N / m. When the system is at rest, d = 0.5 m. The system rotates around a fixed z-axis. In the case where d = 0.12 m, what is the coefficient of friction for the cylinder to have a constant velocity of 9.825 m / s?
1.) A 300-lb block rests on a plane inclined at 36.87° from the horizontal. A 100 lb force pushes this block up the plane. The coefficient of friction between the block and the plane shown is 0.35. If the block is in equilibrium, determine the magnitude of the friction force. a. 63 lb b. 280 lb c. 80 lb d. 84 lb 2.) Find the component of F = 5 Ni + 3 Nj + 2 Nk along the vector r = 3 mi − 4 mj. a. Fr = 5.4 N b. Fr = 4.4 N c. Fr = 6.4 N d. Fr = 5.14 N
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?
A 100 N force acts as shown on a 30.6 kg block placed on an inclined plane. The coefficients of friction between the block and the plane are µs = 0.25 and µk = 0.2. Determine whether the block is in equilibrium and find the value of the friction force.
In a porter governor the mass of the central load is 18 kgand the mass of each ball is 2kg. the top arms (250+X) mm while the bottom arms are (300+X) 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 Note X is the student roll no. for example if the student roll no is A20 then X=20
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?
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
The crate shown is held against wedge B by a spring. The spring is 92.5% of its original uncompressed length l=2.50m , and the spring constant is given as k=1350N/m . The coefficient of static friction at all contacting surfaces is μs=0.150 . The mass of the crate is m=28.0kg . The angle is θ=14.0∘ . Neglect the mass of the wedge. Assume the crate only moves in the y direction and that wedge A cannot move.(Figure 1) Part A - Determining the normal force exerted by the crate on the wedge Determine the normal force Nc that the crate exerts on the wedge when the system is at rest. Express your answer to three significant figures and include the appropriate units. Part B - Finding the smallest horizontal force P to move the crate upward Determine the magnitude of the smallest horizontal force P that is necessary to begin moving the crate upward. Express your answer to three significant figures and include the appropriate units.
A 4.6-kg block is pushed 2.3 m up a vertical wall with constant speed by a constant force of magnitude F applied at an angle of ? = 30° with the horizontal, as shown in the figure below. If the coefficient of kinetic friction between block and wall is 0.30, determine the following. A figure, drawn from a side view, shows the right side of a rectangular block pushed up against a rough, vertical wall. A force vector F acts on the block and is represented by a diagonal rrow pointing up and to the right, toward the center of the block's left side. The arrow forms an angle ? with the horizontal. (a) the work done by F J(b) the work done by the force of gravity J(c) the work done by the normal force between block and wall J(d) By how much does the gravitational potential energy increase during the block's motion? J
the system blocks shown below is in equilibrium, the weight of block A is 10 kN and for block B is 35 kN . The coefficient of friction between A and surface is 0.2 and between two block A and B is 0.15. Answer the following: The direction of friction force between two blocks which effect on block A is in * First Quarter Second Quarter Third Quarter Fourth Quarter The value of friction force between two blocks is * 5.6 kN 6.4 kN 4.8 kN Non above-mentioned The value of friction force between block A and its surface is * 4.0 kN 5.5 kN 6.2 kN Non above-mentioned The coefficient of friction between block B and surface is * 5 نقاط 0.24 0.63 0.56 0.37 The value of friction force between the block B and it's surface is * 25 kN 35 kN 15 kN Non above-mentioned The system is in * Equilibrium Impending to motion Kinematic