An aerofoil wing in its first bending and torsional modes can be represented schematically as shown in figure 5.28 con- nected through a translational spring of stiffness k and a torsional spring of stiffness kr. Write the equations of motion for the system and obtain the two natural frequencies. Assume the following data: m = 5 kg, k = 5 x 10 N/m. a = 0.1 m I = 0.12 kg m2, kr=0.4 x 103 Nm/rad, m.l k KT