Problem 1 The motor mounted on the bracket is acted on by its 160N weight and its shaft resists a repeated thrust load of 120N and a repeated couple of 25Nm that are applied to it. If the motor is fixed to the bracket by four bolts and the stress concentration factors for shear stress is 2.5 and for normal and bending stresses are 2.1, determine the diameter of the bolts for a static and fatigue factor of safeties that are more than 4. Note that: a. The horizontal distance between the bolts and the shaft's axis is 100mm and the endurance limit is 129MPa b. Choose the diameter of the bolts from Metric Mechanical-Property class T 200 mm -75 mm 160 N 75 mm 25 N-m 120 N 100 mm si