angular speed question!! please help right away!

[apgym2]

a pencil, 15.7 cm long, is released from a vertical position with the eraser end resting on a table. The eraser does not slip. Treat the pencil like a uniform rod. what is the angular speed of the pencil just before it hits the table?

i know i have to use conservation of energy, but im not sure where center of mass fits in.. please help

the answer choices are:
a. 11.2 rad/s
b. 7.23 rad/s
c. 24.5 rad/s
d. 16.8 rad/s


any help or guidance would be much appreciated..thank u!

[Doc Al]

i know i have to use conservation of energy, but im not sure where center of mass fits in..

In figuring the change of PE of the pencil, use the change in height of the center of mass. The PE gets converted to rotational KE.