$3\mathrm{.}11$ and $3\mathrm{.}12$ The tailgate of a car is supported by the hydraulic lift $BC.$ If

the lift exerts a $125-lb$ force directed along its centerline on the ball

and socket at $B,$ determine the moment of the force about $A.$

Fig. P$3\mathrm{.}11$

Fig. P$3\mathrm{.}12$