Chapter 11, Problem 102P

A 4-m × 5-m × 7-m room is heated by the radiator of a steam-heating system. The steam radiator transfers heat at a rate of 10,000 kJ/h, and a 100-W fan is used to distribute the warm air in the room. The rate of heat loss from the room is estimated to be about 5000 kJ/h. If the initial temperature of the room air is 10°C, determine how long it will take for the air temperature to rise to 25°C. Assume constant specific heats at room temperature. The gas constant of air is R = 0.287 kPa·m3/kg·K (Table A-1). Also, cv = 0.718 kJ/kg·K for air at room temperature (Table A-2).   Steam enters the radiator system through an inlet outside the room and leaves the system through an outlet on the same side of the room. The fan is labeled as W sub p w. The heat is given off by the whole system consisting of room, radiator and fan at the rate of 5000 kilojoules per hour.   It will take 831  Numeric ResponseEdit Unavailable. 831 incorrect.s for the air temperature to rise to 25°C.

A piston–cylinder device contains 50 kg of water at 250 kPa and 25°C. The cross-sectional area of the piston is 0.1 m2. Heat is now transferred to the water, causing part of it to evaporate and expand. When the volume reaches 0.26 m3, the piston reaches a linear spring whose spring constant is 100 kN/m. More heat is transferred to the water until the piston rises 20 cm more. NOTE: This is a multi-part question. Once an answer is submitted, you will be unable to return to this part.       Determine the final pressure and temperature.   The final pressure is  kPa. The final temperature is  ºC.   Find the work done during the process

A garden hose attached with a nozzle is used to fill a 20-gal bucket. The inner diameter of the hose is 1 in and it reduces to 0.53 in at the nozzle exit. The average velocity in the hose is 8 ft/s and the density of water is 62.4 lbm/ft3.   NOTE: This is a multi-part question. Once an answer is submitted, you will be unable to return to this part.   Determine the volume and mass flow rates of water through the hose.    The volume flow rate of water through the hose is  ft3/s.   The mass flow rate of water through the hose is  lbm/s. The change in time? What is the exit velocity?