Relative velocities of rigid bodies

AI Thread Summary
The discussion revolves around determining the velocities and angular velocity of a triangular body undergoing rotation. Given the angles and rotation rates, the equations for relative velocities are applied, specifically vB = vE + w x rB/E and vB = vA + w x rB/A. The user successfully calculates vB as -10i but struggles with the next steps, particularly in deciding whether to use theta_dot or a different angular velocity for the link AD. The absence of a diagram is noted as a significant barrier to understanding the problem fully. Clarity on the angular velocities and the need for visual aids is emphasized for solving the problem effectively.
kdm06
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Homework Statement



A triangular body changes orientation as the suspporting links rotate. At the moment shown, theta = 90 deg, theta_dot = 5 rad/s, and beta = 45 deg. Determine vA and the angular velocity of the triangular body.
rB/C = 2j cm and rB/A = 5i cm

Points E and D are fixed. theta is the angle made between horizontal and BE. beta is angle made between horizontal and AD.

Homework Equations



vB = vE + w x rB/E
vB = vA + w x rB/A

The Attempt at a Solution



vB=vE + w x rB/E
vB=0 + 5k x 2[]j[/b]
vB=-10i

vB=vA + w x rB/A
-10i = vA + w x 5j


I am stuck at this point because I am not sure if I should use theta_dot for this w because AD is at a different angle (beta). And if I do need to use a different w (which would be beta_dot how would I find it without knowing the length of AD.
 
Last edited:
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Where's the diagram?
 
Shooting star said:
Where's the diagram?

ya.. please if diagram is to be provided.. do not omit it.
 

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