EXAMPLE 3: KINEMATICS OF RIGID BODIES

 

 

The robot arm is constructed from two bars OA and AB as shown in the figure. At the instant shown, bar OA is rotating clockwise at an angular speed of  and bar AB is rotating counter clockwise at a rate of . Calculate the velocity of B.

 


SOLUTION:

 

 

Both OA and AB are of constant length, therefore

Substitution into (1) gives