Answer: 169,98 m
Explanation: The final height Lf will be calculated according to a formula that includes a change in length, that is height ΔL, while the initial length is L₀.
Lf = L₀ + ΔL
Change in length i.e. height ΔL, depend on the change in temperature. The α linear expansion coefficient is also used incorporating material characteristics and their relationship to temperature change, while the change in temperature is ΔT.
α = 2,5 · 10 ⁻⁶ /°C for marble
We will express the change in length ΔL as the product of the initial length L₀, the alpha coefficient and the temperature change ΔT.
ΔL = α · L₀ · ΔT = 2,5·10⁻⁶ · 170 · 45° = - 0.019125 m
So that the final length Lf:
Lf = L₀ + ΔL = 170 - 0.019125 = 169,98 m