A 0.5-lb block B fits inside a small cavity cut in arm OA, which rotates in the vertical p...

A 0.5-lb block B fits inside a small cavity cut in arm OA, which rotates in the vertical plane at a constant rate such that υ = 9 ft/s. Knowing that the spring exerts on block B a force of magnitude P = 0.3 lb and neglecting the effect of friction, determine the range of values of θ for which block B is in contact with the face of the cavity closest to the axis of rotation.