Question

A 10°C fall in temperature is equal to

(a) 10°F fall in temperature
(b) 18°F fall in temperature
(c) 10°F rise in temperature
(d) 18°F rise in temperature

Answer 1

(b) 18°F fall in temperature
Assume,

	Initial Temperature	Final Temperature
In Celcius Scale	C1	C2
In Fahrenheit Scale	F1	F2

^oC₂ - ^oC₁ = -10^oC
As, ^oC = ($\frac{5}{9}$)(^oF-32)
^oC₂-^oC₁ = ($\frac{5}{9}$)(^oF₂-32) - ($\frac{5}{9}$)(^oF₁-32)
-10^oC = ($\frac{5}{9}$)(^oF₂-^oF₁)
-18^oC = ^oF₂-^oF₁
The negative sign implies that in the Fahrenheit scale temperature decreases by 18^oF.