The two uniform thin discs shown in the figure rest on a horizontal plane and are connected through frictionless pin-joints at A and B by a rigid light rod which remains horizontal. The mass of disc A is 15 kg. and that of disc B is 25 kg. The static coefficients of friction between the plane and discs A and B are, respectively, (,),= 0.2 and (,),= 0.55. At the instant shown, a counter-clockwise moment T = 125 Nm. is applied to disc B. You are required to, (a) identify the type of ensuing motion of the discs, (b) draw the free-body, kinematic and kinetic diagrams of the discs, (c) assuming motion initiates with pure rolling, write down the appropriate kinematic and kinetic relationships with respect to a suitable global axes system, and (d) determine, in magnitude and direction, the angular accelerations of the discs and force developed in the rod AB at the instant the moment T is applied. (e) Validate the pure rolling assumption in part(c) and if slipping is anticipated, explain with supporting arguments, whether one of the discs will first slip, or both discs will slip at the same time.

The two uniform thin discs shown in the figure rest on a horizontal plane and are connected through frictionless pin-joints at A and B by a rigid light rod which remains horizontal. The mass of disc A is 15 kg. and that of disc B is 25 kg. The static coefficients of friction between the plane and discs A and B are, respectively, (,),= 0.2 and (,),= 0.55. At the instant shown, a counter-clockwise moment T = 125 Nm. is applied to disc B. You are required to, (a) identify the type of ensuing motion of the discs, (b) draw the free-body, kinematic and kinetic diagrams of the discs, (c) assuming motion initiates with pure rolling, write down the appropriate kinematic and kinetic relationships with respect to a suitable global axes system, and (d) determine, in magnitude and direction, the angular accelerations of the discs and force developed in the rod AB at the instant the moment T is applied. (e) Validate the pure rolling assumption in part(c) and if slipping is anticipated, explain with supporting arguments, whether one of the discs will first slip, or both discs will slip at the same time.

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 7.24P: A uniform plank is supported by a fixed support at A and a drum at B that rotates clockwise. The...

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