In the gear system shown, a torque of TE= 1220 lb-ft is delivered at gear E. Assume that NA-28 teeth,NB-75 teeth, Nc-25 teeth, ND-50 teeth. Shafts (1)and (2) are solid shafts, and the bearings shownallow free rotation of the shafts. (a)Determine the torque TA provided by the motor-to gear A. (b) If the allowable shear stress in each shaft must-be limited to 4100 psi, determine the minimum-permissible diameter (d₁, d₂) for each shaft.

Fig: 1

Fig: 2

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Fig: 4