Dynamics: Absolute and Relative Acceleration in Plane Motion

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Homework Help Overview

The discussion revolves around a dynamics problem involving a rod on a horizontal table subjected to a force, with specific accelerations given for points A and the angular acceleration of the rod. Participants are tasked with determining the accelerations of points G and B based on the provided information.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Participants express confusion regarding the absence of a normal component of acceleration in the problem. There are attempts to understand the relationship between the given accelerations and the required calculations for points G and B. Questions about the role of forces and the center of mass are also raised.

Discussion Status

The discussion is ongoing, with participants exploring different interpretations of the problem setup and questioning the assumptions made regarding the accelerations involved. Some guidance has been offered regarding the focus on accelerations rather than forces.

Contextual Notes

Participants note that the problem only involves the accelerations provided, and there is a lack of information regarding forces acting parallel to certain points, which may affect the understanding of the problem.

Drew Davison
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Homework Statement


zPRsg3f.png


A force P is applied to the rod which rests on a horizontal table. The following accelerations are produced. aA= 3.6m/s2 to the right, α of the rod = 6 rad/s2 CCW. Determine the acceleration of point G and B

Homework Equations


aG=aA+aG/A
aG=aA+[(aG/A)tangential + (aG/Anormal)]
aG=aA+[(α X rG/A) + ( ω2 * rG/A)]

The Attempt at a Solution


So I tried to solve the problem and quickly found that there is no way to solve for angular acceleration (ω). Looking at the solution they completely leave out the normal component of acceleration to solve for the acceleration at G and A. They just plug in values for acceleration at A, angular acceleration and distance from A to G.

I can't figure out why there is no normal component of acceleration in this problem.
Any help?
Thanks!
 
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is there a force parallel to AG?
 
No only the forces that are show. The evaluation of the question only involves the accelerations
 
Drew Davison said:

Homework Statement


zPRsg3f.png


A force P is applied to the rod which rests on a horizontal table. The following accelerations are produced. aA= 3.6m/s2 to the right, α of the rod = 6 rad/s2 CCW. Determine the acceleration of point G and B

Homework Equations


aG=aA+aG/A
aG=aA+[(aG/A)tangential + (aG/Anormal)]
aG=aA+[(α X rG/A) + ( ω2 * rG/A)]

The Attempt at a Solution


So I tried to solve the problem and quickly found that there is no way to solve for angular acceleration (ω). Looking at the solution they completely leave out the normal component of acceleration to solve for the acceleration at G and A. They just plug in values for acceleration at A, angular acceleration and distance from A to G.

I can't figure out why there is no normal component of acceleration in this problem.
Any help?
Thanks!
Do you know how to work with the center of mass ?
 
Drew Davison said:
No only the forces that are show. The evaluation of the question only involves the accelerations
Then why should there be an acceleration in that direction?
 

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