A bullet of mass 10 g and speed 500 m/s is fired into a door and gets embedded exactly at the centre of the door. The door is 1.0 m wide and weighs 12 kg. It is hinged at one end and rotates about a vertical axis practically without friction. What is the angular speed of the door just after the bullet embeds into it?
a. 6.25 rad/sec
b. 0.625 rad/sec
c. 3.35 rad/sec
d. 0.335 rad/sec