Using the principles to be developed on equilibrium, one can determine that the tension in cable AB is 268.0 N. Determine the moment about the x-axis of this tension force acting on point A. Compare your result with the moment of the weight W of the 18-kg uniform plate about the x-axis. What is the moment of the tension force acting at A about the line OB?

To save energy, the air supply to a 2000 ft office has been shut off overnight and the room temperature has dropped to 40°f. in the morning, the thermostat is reset to 70°f and warm air at 120 f begins to flov in at 200ft'/min. the air is well mixed within the room, and an equal mass flow of air at room temperature (changing with time) is withdrawn through a return duct. the air pressure is nearly 1 atm everywhere. ignoring heat transfer with the surroundings and kinetic and potential energy effects, estimate how long it takes for the room temperature to reach 70°f. plot the room temperature as a function of time.