# Linear Thermal Expansion

Written by Jerry Ratzlaff on . Posted in Thermodynamics

Linear thermal expansion, abbreviated as $$\Delta l$$, also known as line thermal expansion, is a porportional change in the origional length and change in temperature due to the heating or cooling of an object.

## Linear thermal expansion Formulas

 $$\large{ \overrightarrow{\Delta l} = l_f - l_i }$$ $$\large{ \overrightarrow{\Delta l} = \overrightarrow{\alpha_l}\; l_i \; \Delta T }$$

### Where:

 Units English Metric $$\large{ \overrightarrow{\Delta l} }$$ = linear thermal expansion $$\large{ \frac{in}{in\;F} }$$ $$\large{ \frac{mm}{mm\;C} }$$ $$\large{ l_f }$$ = final length $$\large{ft}$$ $$\large{m}$$ $$\large{ l_i }$$ = initial length $$\large{ft}$$ $$\large{m}$$ $$\large{ \overrightarrow{\alpha_l} }$$   (Greek symbol alpha) = linear thermal expansion coefficient $$\large{ \frac{in}{in\;F} }$$ $$\large{ \frac{mm}{mm\;C} }$$ $$\large{ \Delta T }$$ = temperature change $$\large{F}$$ $$\large{C}$$