The following diagram shows three masses m1, m2, m3 connected by line of springs

The following diagram shows three masses m1, m2, m3 connected by line of springs. One case has 4 springs with top and bottom fixed (Call it fixed -fixed). The other case has only three springs, the lowest mass hangs freely (call it fixed -free). fixed end 10 = 0 fixed end uo = 0 spring c1 tension y1 spring c1 tension y1 mass m1 movement u 1 mass m 1 movement u C2 y2 spring C2 tension y2 m2 5 mass m2 movement u 2 V3 spring c3 mass m3 om tension y3 movement u 3 V4 V4 = 0 C4 free end fixed end U4= 0 Find the stiffness matrix for fixed-fixed case. . Find the stiffness matrix for fixed-free case.