The ground is assumed to be at a uniform temperature of 10 Cwhen the top is brought to a temperature of -20 C for 65 days. Atwhat depth in meters is the soil going to reach 0 C and possiblyfreeze water lines? (k_soil = 0.5 W/m K, r = 2000 kg/m^3, Cp = 1800J/kg K) see error function table.

a. 0.93

b. 1.30

c. 1.21

d. 1.17

e. 1.11

W 0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20 0.22 0.24 0.26 0.28 0.30 0.32 0.34 erf w 0.00000 0.02256 0.04511 0.06762 0.09008 0.11246 0.13476 0.15695 0.17901 0.20094 0.22270 0.24430 0.26570 0.28690 0.30788 0.32863 0.34913 0.36936 W 0.36 0.38 0.40 0.44 0.48 0.52 0.56 0.60 0.64 0.68 0.72 0.76 0.80 0.84 0.88 0.92 0.96 1.00 erf w 0.38933 0.40901 0.42839 0.46622 0.50275 0.53790 0.57162 0.60386 0.63459 0.66378 0.69143 0.71754 0.74210 0.76514 0.78669 0.80677 0.82542 0.84270 W 1.04 1.08 1.12 1.16 1.20 1.30 1.40 1.50 1.60 1.70 1.80 1.90 2.00 2.20 2.40 2.60 80 3.00 erf w 0.85865 0.87333 0.88679 0.89910 0.91031 0.93401 0.95228 0.96611 0.97635 0.98379 0.98909 0.99279 0.99532 0.99814 0.99931 0.99976 0.99992 0.99998