The mechanical structure of a rotational system is given as shown. K shows the spring coefficients, B shows the viscous damping coefficients, N shows the number of theeth of gears and J shows the moment of inertia. An external torque T(t) is applied to the system as shown. Draw the equivalent system(without gears) using the "reflecting impedances" method and derive the equations of motion. relle ECC J K T(t) 0.(t) N N D o J K elle 1