8.9 An accelerometer is to measure the angular acceleration of a rotating mixing vessel. The angular position of the vessel varies sinusoidally with time with amplitude 2.5 rad and period 2 s. The rotating seismic mass is equivalent to a mass of 0.1 kg on a weightless arm of length 5 cm. The stiffness of the spring is 2.5 x 102 N m rad and the damping ratio is 1/2. The angular position of the seismic mass is measured with a secondary potentiometric sensor. What should the input range of this sensor be?