$16\mathrm{.}98$ Aball suspended from a string that goes through a hole in the ceiling at O moves with velocity vA path of radius rA$.$ in a horizontal circular The string is then drawn through the hole until the ball moves with velocity vB dius e rB$.$ rA vA $=$ rB vB$.$ in a horizontal circular path of ra Use the principle of angular impulse and momentum to show that Strategy: Let e be a unit vector that is perpendicular to the ceiling. Although this is not a central$-$force problem$$the ball$$s weight does not point toward O$$you can show that so that # $1$r $*$F$2=0,$ e # HO is conserved.