Problem $16\mathrm{.}83$ modified

The $79-$Ibf tailgate of a car is supported by the hydraulic lift BC$.$ If BC fails and the tailgate falls and hits the car with an angular velocity of $4\mathrm{.}7$ra$($d$)/($s$).$ The tailgate can be modeled as a $21$ in $.$ long slender rod. Neglect any rotational resistance at pin$-$joint A$.$

Calculate the angular acceleration of the tailgate immediately before the impact. $\backslash$alpha $=,$k$($ra$($d$)/($s$^(2)))$

Calculate the reaction at A immediately before the impact. F$\_($A$)=$i$+$j $($lbf$)$