A mercury-in-glass thermometer reads -20º at the ice point and 100º at the steam point. Calculate the Celsius temperature corresponding to 70º on the thermometer.
A
62.5\(\circ\)C
B
50.0\(\circ\)C
C
75.0\(\circ\)C
D
41.0\(\circ\)C
Verified Correct Answer: C.
Physical Principles & Numerical Solution
100º → 100
70º → x
-20º → 0
Using the interpolation method
\(\frac{70 -(-20)}{100 -(-20)}\) = \(\frac{x - 0}{100 - 0}\)
\(\frac{90}{120} = \frac{x}{100}\)
120x = 90 x 100 = 9000
x = \(\frac{9000}{120}\) = 75.0ºC
Source: WAEC / JAMB / NECO Classroom Archive (Record #76339)