4-79 White potatoes and
\alpha =0.13\times
10^(-6)(m^(2))/(s)
) that are initially at a uniform temperature of
25\deg C
and have an average diameter of 6 cm are to be cooled by refrigerated air at
2\deg C
flowing at a velocity of
4(m)/(s)
. The average heat transfer coefficient between the potatoes and the air is experimentally determined to be
19(W)/(m^(2))*K
. Determine how long it will take for the center temperature of the potatoes to drop to
6\deg C
. Also, determine if any part of the potatoes will experience chilling injury during this process.