
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
_{}_{}