### Rigid Body

A homogeneous ball (mass $m$, radius $r$) is struck by a horisontal force $F$ in the point which is above the center by the distance $l. The time $t$ of force action is very small, but $Ft$ is nonzero. Find the velocity of the center-of-mass and the angular velocity of the ball around the axis which goes through the center-of-mass, if a) there is no friction with the floor, and b) if the friction prevents sliding. ($I_{CM}=\frac{2}{5}mr^2$)