Problem I: The system in the figure uses a high power op-amp to drive a motor. An identical motor is used for measuring motor speed. The input to the system is Va, and the output is the motor shaft speed. Develop an equation for the op-amp portion using Vt and Va as inputs, and V. as the output. Find differential equations for the permanent magnet DC motors. Assume all components are ideal. The motors are identical with a resistance of 20 ohms. With an input voltage of 5V the connected motors spin at 2000RPM, and have a time constant of 0.25s. Draw a block diagram for the system shown in the figure. Put values in each of the blocks. Simulate the system on Matlab/Simulink 1K IK Op Amp IK V Motor Vd luf PIK