A permanent-magnet dc motor is to be started from rest. Ra=0.35O, La=1.5 mH, Ke=0.5 V/(rads/s), Kt= 0.5 Nm/A, and Jm= 0.02 Kg.M^2. This motor is driving a load of inertia Jl= 0.04 kd-m^2. At some instant, its speed is to decrease linearly and reverse to 100 rads/sec in a total of 4 seconds. Neglect La and friction. Calculate and plot the required current and the resulting voltage Va that should be applied to the armature terminals of the machine. As intermediate steps, calculate and plot Ea, the required electromagnetic torque Tem from the motor, and the current Ia.