Question

A brass rod is 2m long at a certain temperature.what is its length for a temperature rise of 100kelvin if the expansivity of brass is 18 ×10^-6

Answer 1

By the definition of the linear thermal expansion, we have:

$$\Delta L= L_0\alpha\Delta T,$$ $$L-L_0= L_0\alpha\Delta T,$$ $$L=L_0(1+\alpha\Delta T),$$ $$L=2\ m\cdot(1+18\cdot10^{-6}\ K^{-1}\cdot100\ K)=2.0036\ m.$$