Abar ab weighing w = 150 lb is supported at a by a fixed collar and at b by a pin in a slot. the fixed collar at a can freely move along the vertical rod cd. the pin in the slot at b allows free movement along ab. determine the magnitude of the reactions at a using decoupled equations of equilibrium. draw a complete and clear fbd. note: an equation used to calculate a reaction is decoupled if it has a single unknown reaction and does not involve previously calculated reactions.