A group of 30 students attend a class in a room that measures 10 m by 8 m by 3 m. Each student takes up about 0.075 m³ and gives out about 80 W of heat (l W = l J/s). Calculate the air temperature rise during the first 15 minutes of the class if the room is completely sealed and insulted. Assume the heat capacity, C_υ. for air is 0.718 kJ/(kg K). Assume air is an ideal gas at 20^oC and 101.325kPa. Note that the heat absorbed by the air Q is related to the mass of the air m, the heat capacity, and the change in temperature by the following relationship:

The mass of air can be obtained from the ideal gas law: PV = m/Mwt RT. Where P is the gas pressure, V is the volume of the gas, Mwt is the molecular weight of the gas (for air, 28.97 kg/kmol), and R is the ideal gas constant [8.314 kPa m³/(kmol K)].

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C,dT = mC,(T; – T1) = m