Chapter U3.5, Problem 5E

Interpretation Introduction

Interpretation : Out of one Celsius degree, one Kelvin and one Fahrenheit degree, the smallest unit has to be identified.

Concept Introduction : There are three types of temperature scales, a Celsius scale, a Kelvin scale and a Fahrenheit scale. Celsius scale was created by Andreas Celsius in 1747 and Fahrenheit scale was created by German scientist Daniel Fahrenheit in 1724. Lord Kelvin proposed the Kelvin scale in 1848.

Answer to Problem 5E

One Kelvin is the smallest unit.

Explanation of Solution

In Celsius scale, the melting temperature of ice is ${\text{0}}^{\text{0}}\text{C}$

On the Fahrenheit scale, the melting temperature of ice is ${32}^{\text{0}}\text{F}$ .

On the Kelvin scale, the melting temperature of ice is $\text{0+273=273K}$

Therefore, ${\text{0}}^{\text{0}}{\text{C=32}}^{\text{0}}\text{F=273K}$

  $1^{\text{0}}{\text{C=1}}^{\text{0}}\text{C}$

Now using the formula,

  $\text{F=}\frac{\text{9}}{\text{5}}\text{C+32}$

  $1^{\text{0}}\text{F=-17}{\text{.3}}^{\text{0}}\text{C}$

Since, ${\text{0K=-273}}^{\text{0}}{\text{C,1K=-272}}^{\text{0}}\text{C}$

Comparing the values of $1^{\text{0}}{\text{C, 1}}^{\text{0}}\text{F and1K}$ one can say that Kelvin is the smallest unit.

Conclusion

Most of the scientific calculations and experiments use Kelvin scale of temperature. Kelvin is also the S.I unit of temperature.