The 80-lb boy stands on the beam and pulls with a force of 40 lb. If (μs)D = 0.4, determin...

The 80-lb boy stands on the beam and pulls with a force of 40 lb. If (μs)D = 0.4, determine the frictional force between his shoes and the beam and the reactions at A and B.Hie beam is uniform and has a weight of 100 lb. Neglect the size of the pulleys and the thickness of the beam.