Question

The brass rod is 2m long at a certain temperature. What is the length for a temperature rise of 100k, if the expansivity of brass is 18 × 10^-6k^-1?

Answer 1

By definition, the gain in length will be:

$$\Delta L = \alpha L_0\Delta T$$

where $\alpha = 18\times 10^{-6}K^{-1}$ is the expansivity, $L_0 = 2m$ is the initial length, and $\Delta T = 100K$ is the change in temperature. Thus, obtain:

$$\Delta L = 18\times 10^{-6}\cdot 2\cdot 100 = 3.6\times 10^{-3} = 0.0036m$$

Hence, the final length will be:

$$L = L_0 + \Delta L = 2m + 0.0036m = 2.0036m$$

Answer. 2.0036m.