(a) State Kennedy’s Theorem for instant centres and show how it is used to find the centres. Illustrate your answer using sketches of a 4-bar linkage and show how the method be used to find velocity and acceleration at any point in a linkage.  (b) In the four-bar linkage mechanism shown in Figure Q5b link AD is fixed and is 15 cm long. The crank AB is 5 cm long and rotates at 120 rpm clockwise while link CD which rotates about Dis 8 cm long. The connecting link BC is 11 cm in length. The angle, <BAD, is 60°. (i) Find the angular velocity of link CD.  For the mechanism shown in Figure Q5b the torque being input at the crank AB is 10 Nm. What is the torque being delivered at the output link CD.