An aluminum vat is 19 m long at room temperature (20°C). How much longer is it when it contains boiling water at 1 atm pressure?

Answer 1

One atmosphere of pressure equals 101325 Pascals or 101325 Newtons Per Square Meter

and is simply the air pressure one feels at sea level with temperature around 20°C (or 68°F).

Take the coefficient of linear expansion for aluminum as α = 2.31E-5 (C°)^-1.

Write the relation α = 1/l × Δl/ΔT enumerated to 2.31E-5 (C°)^-1 = 1/(19 m) × Δl/(100 − 20) C^°

which isolates change in length Δl as 0.035112 m ≈ 35 mm.