The dynamic imbalance of a certain crankshaft is approximated by the physical model show...

The dynamic imbalance of a certain crankshaft is approximated by the physical model shown, where the shaft carries three small 1.5-lb spheres attached by rods of negligible mass. If the shaft rotates at the constant speed of 1200 rev/min, calculate the forces R_A and R_B acting on the bearings. Neglect the gravitational forces.