Simplify the Young's modulus formula E=FL3/318 using the provided information. • The force, F, applied to each beam is 4/10 lb.
• The length, L, of each beam is 10 in.
• The moment of inertia, 1, for each beam is 1.628 x 10-4 in.

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 the air is well mixed within the room, and an equal mass flow of air at room temperature (changing with time) is withdrawn through a return duct.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.