Once again, the relative velocity equation is used to determine the velocity of a point on a rotating and translating bar.
v_{C} = v_{B}
+ v_{C/B} = v_{B} + ω_{BC} × r_{C/B}
The velocity of point B is known from previous analysis and the velocity of point C is constrained in the vertical direction. The angular velocity ω_{BC} is not known.
v_{C}j = 
314.2 cosθi  314.2 sinθj +
ω_{BC}k × (
3"sinαi + 3"cosαj )
Completing the cross product and equating the i and j components gives,
i: 0 = 314.2 cosθ  3ω_{BC} cosα
j: v_{C} = 314.2 sinθ + 3ω_{BC} sinα The two angles θ and α are actually related (see diagram). The horizontal distance of both arms must equal each other since points A and C always aligned in the vertical direction.
(3 in) sinα = (1 in) sinθ
Substituting α = sin^{1} (sinθ /3)
into the i terms and solving for ω_{BC} gives, gives
This can now be used with the j terms to solve for the velocity of C in terms of the angle θ,
