Answer to Question #299478 in Physics for Ashley

Question

A metal bar 50cm long at 15°c is heated to 85°c. If it expands by 0.088cm, determine its linear expansivity.

Answer 1

Given:

$l_0=50\:\rm cm$

$\Delta l=0.088\:\rm cm$

$\Delta t=70\:\rm K$

The thermal expansion is described by an equation

$\Delta l=l_0\alpha\Delta t$

Hence, the linear expansivity

$\alpha=\Delta l/(l_0\Delta t)$

$\alpha=\rm 0.088\: cm/(50\: cm*70 \: K)=2.1*10^{-5}\: K^{-1}$