Two children push on opposite sides of a door during play. Both push horizontally and perpendicular to the door. One child pushes with a force of 165 N at a distance of 0.700 m from the hinges, and the second pushes at a distance of 0.450 m. What force (in N) must the second exert to keep the door from moving? Assume friction is negligible. N Suppose a horse leans against a wall as in the figure below. F wall CG 1.2 m 1.4 m (a) 0.35 m (b) Calculate the force exerted on the wall assuming that force is horizontal and using the data in the schematic representation of the situation. Note that the force exerted on the wall is equal in magnitude and opposite in direction to the force exerted on the horse, keeping it in equilibrium. The total mass of the horse and rider is 575 kg. Take the data to be accurate to three digits. N A sandwich board advertising sign is constructed as shown in the figure below. Hinge Chain G2011 Brooks/Cole Thomson Learning 0.50 m 1.30m CG CG Uniform board (CG at center) 1.10 m The sign's mass is 8.00 kg. (a) Calculate the tension in newtons in the chain assuming no friction between the legs and the sidewalk. N (b) What force is exerted in newtons by each side on the hinge? N Suppose you use an ideal pulley of the type shown in image (a) in the figure below to support a car engine of mass 115 kg. T MA=2 MA = 3 MA=4 T TTTT T T T W (a) (b) (a) What would be the tension in newtons in the rope? N W (c) W (b) What force in newtons must the ceiling supply, assuming you pull straight down on the rope? Neglect the pulley system's mass. N