A$\mathrm{.}4$ When a man returns to his well$-$sealed house on a summer day, he finds that the house is at $35C.$ He turns on the air conditioner, which cools the entire house to $20C$ in $30$ min $.$ the power drawn by the air conditioner. Assume the entire mass within the house is equivalent to $800$ kg of air for which $c_1=0\mathrm{.}72k\frac{J}{k}g*C$ and $c_p=1\mathrm{.}0k\frac{J}{k}g*C.$