A Wheel Is Rotating Freely with an Angular Speed of 20

Multiple Choice

A wheel is rotating freely with an angular speed of 20 rad/s on a shaft whose moment of inertia is negligible.A second identical wheel,initially at rest,is suddenly coupled to the same shaft.The angular speed of the coupled wheels is

A) 10 rad/s
B) 14 rad/s
C) 20 rad/s
D) 28 rad/s
E) 40 rad/s