Adigital lowpass butterworth filter is to be designed according to the following specifications: the passband magnitude is constant to within 0.85 db for frequencies below 0.12r and the stopband attenuation is greater than 20 db for frequencies between 0.6m and t. sketch the figure describing these specifications

The space between two 15-in.-long concentric cylinders is filled with glycerin (viscosity = 8.5 × 10-3 lb·s/ft2). the inner cylinder has a radius of 1 in. and the gap width between cylinders is 0.1 in. determine (a) the torque and (b) the power required to rotate the inner cylinder at 180 rev/min. the outer cylinder is fixed. assume the velocity distribution in the gap to be linear.