Question

4. An iron rod of length 30cm is heated thru temperature of 50kelvin. Calculate (a)it's new length (b) it's increase in length.( Linear expansivity of iron= 0.000012/k.)

Answer 1

$\sf{(a)\quad L'=L(1+\alpha\ \Delta T)}$

$\longrightarrow\sf{\ \ L'=30\times10^{-2}(1+1.2\times10^{-5}\times50)}$

$\longrightarrow\sf{\underline{\underline{\ \ L'=30.018\ cm}}}$

$\sf{(b)\quad \Delta L=L'-L}$

$\longrightarrow\sf{\underline{\underline{\Delta L=0.018\ cm}}}$