Question

depth(m) temp(C
25 5.50
50 5.20
75 5.10
100 5.10
125 5.30
150 5.50
175 5.75
200 6.00
225 6.25
250 6.50
275 6.75
300 7.00
Table 1.18 gives the average temperature, T, at a depth d, in a borehole in Belleterre, Quebec.13 Evaluate ΔT/Δd on the the following intervals, and explain what your answers tell you about borehole temperature.
(a) 25 ≤ d ≤ 150
(b) 25 ≤ d ≤ 75
(c) 100 ≤ d ≤ 200

Answer 1

a.) For 25 ≤ d ≤ 150;
ΔT/Δd = (5.50 - 5.50)/(150 - 25) = 0/125 = 0

b.) For 25 ≤ d ≤ 75;
ΔT/Δd = (5.10 - 5.50)/(75 - 25) = -0.4/50 = -0.008

c.) For 100 ≤ d ≤ 200;
ΔT/Δd = (6.00 - 5.10)/(200 - 100) = 0.9/100 = 0.009