Answer:
The height above sea level at <em>B</em> is approximately 1,604.25 m
Step-by-step explanation:
The given length of the mountain railway, AB = 864 m
The angle at which the railway rises to the horizontal, θ = 120°
The elevation of the train above sea level at <em>A</em>, h₁ = 856 m
The height above sea level of the train when it reaches <em>B</em>, h₂, is found as follows;
Change in height across the railway, Δh = AB × sin(θ)
∴ Δh = 864 m × sin(120°) ≈ 748.25 m
Δh = h₂ - h₁
h₂ = Δh + h₁
∴ h₂ ≈ 856 m + 748.25 m = 1,604.25 m
The height above sea level of the train when it reaches <em>B</em> ≈ 1,604.25 m
