Consider building model on pages $\backslash (7-9\backslash )$ of the lecture notes. Model the columns as massless bending beams, floors as massless rigid bodies, and assume that the floors move vertically in the $\backslash ($ X Z $\backslash )-$ plane. Find the vertical displacement $\backslash ($ u $\backslash )$ of the loading point as function of the weight $\backslash ($ F $\backslash )$ on the loading tray and thereby the effective stiffness $($spring coefficient$)\backslash ($ k $\backslash )$ of the structure defined by $\backslash ($ F$=$k u $\backslash ).$ Use the displacement$-$force relationship for a typical column shown to deduce the displacement of the second floor.