A Building Frame Structure Consists Of A Rigid Horizontal Member Bc Of Mass M Suppor 3521997

A building frame structure consists of a rigid horizontal member BC of mass m supported by two vertical columns each of whose bending stiffness is El. Neglect the effect of the weight of BC on the stiffness of the vertical members, (a) Determine the equation of motion of mass m. (b) How would the equation of motion differ if the left-hand column had a stiffness 2EI with no other changes to the structure?