Problem for extra credit 1) In a four bar mechanism ABCD, AD is fixed and is 150 mm long. The crank AB is 40 mm long and rotates at 120 rpm clockwise, while the link CD 80 mm oscillates about D. Link BC and AD are of equal length. Using the analytical/mathematical solution methods find the angular velocity of link CD, when angle BAD=60°. (Note: Example problem 3.3 from the text book can be helpful in this regard) 40 B 60° 150 150 80 C