Problem

Bearings A and B in Fig. 1 rest on immovable supports. Bearing at C is located at the cent...

Bearings A and B in Fig. 1 rest on immovable supports. Bearing at C is located at the center of a simply supported 6-in. I-beam 12 ft long. Let a fill be placed under this bearing so that all bearings are at the same elevation before load is applied. Neglect dead load of the shaft.

(a) Find reactions at A, B, and C.
(b) If the bearing at C is resting on an unyielding support, find the three reactions.
(c) What change in elevation of bearing at C must be made if the bending moments in the shaft are to be numerically equal at the load and at bearing C?
(d) With the bearing at C supported by the beam, find the fill under the bearing required to make the bearing load equal to 750 lb.