As shown, a submarine hatch door is to be opened by applying two oppositely oriented forces of equal magnitudeF=50.0lb at points A and B on the hatch door wheel. The radii of the wheel's inner and outer rings are r1 = 1.90ft andr2 = 0.500ft , respectively. (Figure 1) Calculate the moments MA and MB about point D for the forces applied at pointsA and B. Then, determine the resulting couple moment MR. Assume that a positive moment produces a counterclockwise rotation whereas a negative moment produces a clockwise rotation.
Express your answers numerically in pound-feet to three significant figures separated by commas.