Given the following equation and dBA levels: Legf24)= 10 log ((10(し1/10) + 10(L2/10) + etc + 10(L24))/24) dBA 12am - 1am 50 1am - 2am49 2am 3am 47 3am - 4am 47 4am - 5am 49 5am 6am 57 6am - 7am 64 7am - 8am 67 8am - 9am 65 9am 10 am 66 10am- 11am 64 11am 12pm 65 12pm 1pm 66 1pm 2pm 65 2pm - 3pm 64 3pm - 4pm 65 4pm - 5pm 66 5pm 6pm 66 6pm - 7pm 65 7pm - 8pm 62 8pm 9pm 60 9pm - 10pm 59 10pm 11pm 55 11pm 12am 53 Calculate the Leą 24hr) and the Ldp.

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 the air is well mixed within the room, and an equal mass flow of air at room temperature (changing with time) is withdrawn through a return duct.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