Chapter 17, Problem 88P

Pravinbhai

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2. Consider the 5-1lb bar with length of 2½ feet and width of 2 inches. Small frictionless bearings are mounted to the ends, constraining the motion of the bar to the horizontal x and y slots. The bar starts at rest at positioned at 0= 45°. If an angular acceleration of 3 rad/s² is desired, what moment M must be applied to the bar? What are the reaction forces at A and B at that instant? Additional question: Does the width of the bar matter, or is it appropriate to consider the bar as a slender rod? Consider errors of less than 2% negligible.

2. A cord is wrapped around a homogeneous disk of radius r = 0.5 m and mass m = 14. 25 kg. If the cord is pulled upward with a force T of magnitude 171 N, determine a. the acceleration of the center of the disk, b. the angular acceleration of the disk, c. the acceleration of the cord. T 0.5 m Go A Draw the Free Body Diagram.

4 The uniform 16.1-lb slender bar is hinged about a horizontal axis through O and released from rest in the horizontal position. Determine the distance b from the mass center to O which will result in an ini- tial angular acceleration of 16.1 rad/sec?, and find the force R on the bar at O just after release. G 12" 12"

If P = 30 lb, determine the angular acceleration of the 50-lb roller. Assume the roller to be a uniform cylinder and that no slipping occurs

The 1.8-kg uniform bar rotates in the vertical plane about the pin at O.When the bar is in the position shown, its angular velocity is 4 rad/s, clockwise. For this position, find (a) the angular acceleration of the bar; and (b) the magnitude of the pin reaction at O.

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 crank OA rotates in the vertical plane with a constant clockwise angular velocity ωo of 4.5 rad/s. For the position where OA is horizontal, calculate the force under the light roller B of the 10-kg slender bar AB.