Q8: The 25-kg bar BD is attached to the two light links AB and CD and moves in the vertical plane. The lower link is subjected to a clockwise through its shaft at A. If each link has an angular velocity w = 5 rad/s as it passes the horizontal position, calculate the force which the upper link exerts on the bar at D at this instant. Also find the angular acceleration of the links at this position. torque M = 200 N. m applied %3D

Q8: The 25-kg bar BD is attached to the two light links AB and CD and moves in the vertical plane. The lower link is subjected to a clockwise through its shaft at A. If each link has an angular velocity w = 5 rad/s as it passes the horizontal position, calculate the force which the upper link exerts on the bar at D at this instant. Also find the angular acceleration of the links at this position. torque M = 200 N. m applied %3D

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 7.79P: The coefficient of rolling resistance between the 30-kg lawn roller and the ground is r=0.1. (a)...

See similar textbooks

Similar questions

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.
Two bodies A and B, each weighing 96.6 lb, are connected by a rigid bar of negligible weight attached to them at their gravity centers. The coefficient of friction at the wall and floor is 0.268 if the bodies start from rest at the given position, determine the acceleration of B at this instant. Simplify the solution by creating dynamic equilibrium and taking a moment summation about the intersection of the wall and floor reactions. Explain why these reactions pass through the gravity center of B and A respectively.
In a governor of the Hartnell type the arms of the bell-crank leversare equal in length, and those carrying the operating masses arevertical when the governor is rotating at its mean speed of 775rev/min, with the masses moving in a circle of 175 mm diameter -The usual central controlling spring is replaced by two paralleltension springs direetly connecting the operating masses. Find(a) the magnitude of each operating mass if a force of 90 N isrequired at the sleeve to maintain it in the mean speed positionwhen the specd is increased from 775 to 800 rev/m in(b) the stiffness, or rate, of each spring if the ratio of sleevemovement to increase of speed is 1 mm to 10 revImin when inthe mean speed position.
The arms of a Porter governor are 300 mm long. The upper arms are pivoted on the axis of rotationand the lower arms are attached to the sleeve at a distance of 35 mm from the axis of rotation. The loadon the sleeve is 54 kg and the mass of each ball is 7 kg. Determine the equilibrium speed when the radius of the balls is 225 mm. What will be the range of speed for this position, if the frictional resistances to the motion of the sleeve are equivalent to a force of 30 N?[Ans. 174.3 r.p.m. ; 8.5 r.p.m.]
The velocity of the 8-kg cylinder is 0.3 m∕s at a certain instant. The speed v after dropping an additional 1.5 m is 2.5 m/s. The mass of the grooved drum is 12 kg, its centroidal radius of gyration is k = 210 mm, and the radius of its groove is ri = 200 mm. The frictional moment at O is a constant 3 N∙m. Find the frictional force.
A motorcycle and rider have a combined mass of 350kg. The each wheel has a mass of 20kg with the diameter of 500 mm. The rider accelerates from 5m/s to 25m/s over a distance of 100m, whilst climbing a hill of slope 1 in 20. Identify the magnitude and effect of gyroscopic reaction torque by calculating the angular velocity and power as the motorcycle ascends the incline when the motorcycle and rider travel at 80 km/h around a left-hand bend of road with the radius 30 m.Explain the effects of energy transfer in mechanical systems (e.g. gears, pulley or flywheel) with uniform acceleration present.
The body A with a mass of 50 kg is in equilibrium with the help of the pulling force generated in the AB and AC cables in the middle of the inclined plane and the friction force between the curved surface and the object. The friction force is on the line of motion of body A and develops in the opposite direction to the movement in the direction of the arrow shown in the drawing. Since the pulling force in AB and AC cables is 15.1 and 22.1 N, respectively, calculate the balancer friction force acting on the object vectorially? (g = 9.81 m / s'2)
The double pulley shown in the figure is formed by two wheels that are coupled to each other. The complete pulley (formed by the two wheels) has a mass of 15 kg and a turning radius of 110mm. Block A has a mass of 40 kg. If a force of 2 kN is applied to the tied rope of the inner pulley wheel, determine the speed of block A after 3 seconds. At the beginning, the whole system was at rest. Disregard the mass of the string and consider that the moment of inertia (kg.m²) of the complete pulley is given by IP = mko²where m is the mass of the pulley and Ko is the radiusspinning
The speed of the pickup truck’s engine is controlled by the Porter governor with4 arms of equal length, and pivot on the axis of rotation. Each ball has a massof 4 kg and the mass of the central load on the sleeve is 20 kg. The radius ofrotation of the ball is 150 mm when the governor begins to lift, and 200 mm whenthe governor is at maximum speed. The initial angular speed of the engine’scrank is 14 rad/s, and it has reached a maximum speed at an acceleration of 0.4rad/s2 after 5 seconds. 2.1. If the speed of the crank of an engine is equal to the speed of its governor,calculate the angle between the upper arm and axis of rotation (?) when thegovernor starts to lift and when it is at maximum speed.(11)2.2. Prove that the length of the governor’s arms is equal.
The man is pedaling his bicycle at a constant speed up a slippery slope of 5%. The man and the bicycle have a total mass of 82 kg centered at G. If the rear wheel is about to slip, find the coefficient of friction u between the tire and the road. If the coefficient of friction were doubled, what friction force would act on the rear wheel? (Why can we neglect the friction under the front wheel?)
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 coefficient of rolling resistance between the 30-kg lawn roller and the ground is r=0.1. (a) Determine the force P required to pull the roller at a constant speed. (b) What force P would be needed to push the roller at a constant speed?