Atraffic light consists of a horizontal member attached to a vertical support post. the horizontal member extends 7 m to the left of the support post and has a constant mass density of 15 kg/m. each traffic light has mass of 10 kg, and the street sign has a mass of 5 kg. make sure the connection between the horizontal member and the vertical support post is strong enough to withstand the forces exerted on the horizontal member. calculate the effects of the forces resulting from the two traffic lights and the street sign on the horizontal member.