Fill in the blanks. If the triangles cannot be shown to be congruent from the information given, leave the triangle's name blank and write CanNot Be Determined (CNBD) in the spot for rule.
∆ARE ≅ ∆ by rule

Amass weighing 16 pounds stretches a spring 8/3 feet. the mass is initially released from rest from a point 2 feet below the equilibrium position, and the subsequent motion takes place in a medium that offers a damping force that is numerically equal to 1/2 the instantaneous velocity. find the equation of motion if the mass is driven by an external force equal to f(t)=cos(2t).