1. The plate described in Problem 9.14 has been used in an experiment to determine the free convection heat transfer coefficient. At an instant of time when the plate temperature was 127°C, the time rate of change of this temperature was observed to be -0.0465 K/s. What is the corresponding free convection heat trans- fer coefficient? Compare this result with an estimate based on a standard empirical correlation.
2. Determine the average convection heat transfer coeffi- cient for the 2.5-m-high vertical walls of a home having respective interior air and wall surface temperatures of (a) 20 and 10°C and (b) 27 and 37°C.