The three small spheres, each of mass m, are secured to the light rods to form a rigid u...

The three small spheres, each of mass m, are secured to the light rods to form a rigid unit supported in the vertical plane by the smooth circular surface. The force of constant magnitude P is applied perpendicular to one rod at its midpoint. If the unit starts from rest at θ = 0, determine (a) the minimum force P_min which will bring the unit to rest at θ = 60° and (b) the common velocity v of spheres 1 and 2 when θ = 60° if P = 2P_min.