The two links OA and OB are connected by a pin joint at O. If the link OA turns with angular velocity $${\omega _1}$$ rad/s in the clockwise direction and the link OB turns with angular velocity $${\omega _2}$$ rad/s in the clockwise direction, then the rubbing velocity at the pin joint O is (where r = Radius of the pin at O)

A. $${\omega _1}{\omega _2}{\text{r}}$$

B. $$\left( {{\omega _1} - {\omega _2}} \right){\text{r}}$$

C. $$\left( {{\omega _1} + {\omega _2}} \right){\text{r}}$$

D. $$\left( {{\omega _1} - {\omega _2}} \right)2{\text{r}}$$

Answer: Option B