Problem 2: The mechanism shown is one of two identical mechanisms attached to the two sides of a 90-kg uniform rectangular door. Edge ABC of the door is guided by wheels of negligible mass that roll in horizontal and vertical tracks. A spring of constant k = 600 N/m is attached to wheel B. Knowing that the door is released from rest in the position = 30° with the spring unstretched, determine the velocity of wheel A just as the door reaches the vertical position. 15 m te B 1.5 m C