The linkage mechanism shown below has two rotating arms linked by a pin (A) sliding in a slot on link OD. At the instant shown, pin A has an upwards velocity of 1.5 m/s; the component of pin A's acceleration in the y-direction is 3 m/s. Calculate the angular acceleration of link OD, expressing your answer to one decimal place in units of rad/s, with counterclockwise rotation as positive. Do not include units in your answer. 225 mm 225 mm 8 450 mm /D 0=45