Two small balls A and B, Each of Mass m, are joined rigidly to the ends of a light rigid rod length $l$. The system lies on a smooth horizontal table. A particle of same mass moving with speed u perpendicularly to rod on the table strikes particle B, as shown, consider the following four situations and find the angular velocity $\omega$ of rod after collision.

	COLUMN - A		COLUMN-B
i)	Rod AB lies freely, collision is elastic	p)	$\omega =\frac{u}{l}$
ii)	Rod AB is hinged in the middle, collision is elastic	q)	$\omega =\frac{u}{2l}$
iii)	Rod AB lies freely, colliding particle sticks	r)	$\omega =\frac{4u}{3l}$
iv)	Rod AB is hinged in the middle, colliding particle sticks	s)	$\omega =\frac{2u}{3l}$