The temperature distribution at a certain time instant through a 50 cm thick wall is prescribed by the relationT = 300 500 x 100 x2 + 140 x3

• A. nWhere temperature t is in degree Celsius and the distance x in meters has been measured from the hot surface. If thermal conductivity of the wall material is 20 k J/m hr degree, calculate the heat energy stored per unit area of the wall
• B. 4100 k J/hr
• C. 4200 k J/hr
• D. 4300 k J/hr
• E. 4400 k J/hr