28. Find the transfer function, G(s)=X3(s)/F(s), for the translational mechanical system shown in Figure P2.13. [Section: 2.5] 6 N/m 2 N-s/m x₁(1) 2 N-s/m 4 kg X2(1) 0000 X3(1) 2 N-s/m 6 N/m 4 kg 0000 4kg Frictionless" FIGURE P2.13 ►√(1)