Question

An iron railroad rail is 700 ft long when the temperature is 30°C. What is its length when the temperature is – 10°C?

Answer 1

Answer:

699.67ft

Explanation:

We are given with,

• α = 1.2×10⁻⁵ / °C
• L₀ = 700 ft
• ΔT = -10°C − 30°C = -40°C

Now, We have to find ΔL:

• ΔL = (1.2×10⁻⁵ / °C) (700 ft) (-40°C)
• ΔL = −0.336

Rounded to two significant figures, the change in length is −0.33ft.

Therefore, the final length is approximately 700 ft − 0.33 ft = 699.67ft.