The mass center of the 3 -lb ball has a velocity of $\left(v_{G}\right)_{1}=6 \mathrm{ft} / \mathrm{s}$ when it strikes the end of the smooth $5-1 \mathrm{~b}$ slender bar which is at rest. Determine the angular velocity of the bar about the $z$ axis just after impact if $e=0.8$.