Answer
0.08 m
Work Step by Step
Assume the height is 300 m in January. Find the increase in the height as the temperature rises by 23 degrees Celsius.
$$\Delta \mathcal{l}=\alpha \mathcal{l}_o \Delta T=(12\times 10^{-6}/C^{\circ})(300m)(23 C^{\circ})=0.08m$$
