A thin rod `AB` of mass `M` and length `L` is rotating with angular speed `omega_(0)` about vertically axis passing through its ends `B` on a horizontal smooth table as shown. If at some instant the hinge at end `B` of rod is opened then which of the following statemtents is `//` are correct about motion of rod?

Options

A. the angular speed of the rod after opening the hinge will remain `omega_(0)`
B. the angular speed of the rod after opening the hinge will be less then `omega_(0)`
C. in the process of opening the hinge the kinetic energy of rod will remain conserved.
D. angular momentum of rod will remain conserved about centre of mass of rod in the process of opening the hinge

Answer

A, C, D

Explanation

Initially `omega_(0)` is not changed. After that `omega_(0)` decreases because `I_(0)omega_(0)=I'omega'` initially `I_(0)` about `B` & later`I'` is about com.
Then kinetic energy and angular momentum both are conserved due to no external torque.