36. As shown in the top view, a disc of mass m is moving horizontally to the right with speed v on a table with negligible friction when it collides with a second disc of mass 2m. The second disc is moving horizontally to the right with speed v/2 at the moment before impact. The two discs stick together upon impact. The kinetic energy of the composite body immediately after the collision is
(A) (1/6)mv2
(B) (1/2)mv2
(C) 2/3mv2
(D) (9/8)mv2
Top View