The volume of a 1-kg copper sphere is not allowed to vary by more than 0.1%. if the pressure exerted on the sphere is increased from 10 bar while the temperature remains constant at 300 k, determine the maximum allowed pressure, in bar. average values of rho, β and κ are kg/m^3, 49.2 × 10^-6 (k)^-1, and 0.776 × 10^-11m2/n respectively

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 the air is well mixed within the room, and an equal mass flow of air at room temperature (changing with time) is withdrawn through a return duct.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