An instantaneous configuration of a four-bar mechanism, whose plane is horizontal, is shown in the figure below. At this instant, the angular velocity and angular acceleration of link Q2 A are ω = 8 rad/s and α = 0, respectively, and the driving torque (T) is zero. The link Q2 A is balanced so tht its centre of mass falls at O2.
Which kind of 4-bar mechanism is O2ABO4?
(a) Double crank mechanism
(b) Crank-rocker mechanism
(c) Double rocket mechanism
(d) Parallelogram mechanism