**Definitions:**

**Rankine** (abbreviations: **R, or °R, or deg R**): is a thermodynamic temperature based on an absolute scale named with regard to the Glasgow University engineer and physicist William John Macquorn Rankine, who proposed it in 1859.

**Kelvin** (abbreviations: **K, or °K, or deg K**): is a unit of measure for temperature based upon an absolute scale, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all thermal motion ceases in the classical description of thermodynamics. It was first proposed in 1848 and is one of the seven base units in the International System of Units (SI).

## How to Convert Degree Rankine to Degree Kelvin

*Example: How many degree Kelvin are equivalent to 91.9 degree Rankine?*

As;

1 degree Rankine = (5/9)*X degree Kelvin

91.9 degree Rankine = Y degree Kelvin

Assuming Y is the answer, and by substitution principle;

Y equals ( (5/9)*91.9 ) over 1, where X is substituted by 91.9

(i.e.) Y = ( (5/9)*91.9 ) / 1 = 51.055555555556 degree Kelvin

Answer is: 51.055555555556 degree Kelvin are equivalent to 91.9 degree Rankine.

*Practice Question: Convert the following units into K:*

N.B.: After working out the answer to each of the next questions, click adjacent button to see the correct answer.

( i ) 25.28 R

( ii ) 20.64 R

( iii ) 21.05 R