A piece of aluminum is surrounded by air at a pressure of 1.01 x 10^5 Pa.?

Question

The aluminum is placed in a vacuum chamber where the pressure is reduced to zero. Determine the fractional change in the volume of the aluminum foil.

Could you please post a detailed answer, thanks.

Answer 1

Important material properties for aluminum is SI units:

E = 68.3 x 10^9 Pa (elastic modulus)

nu = 0.33 (Poisson's ratio)

Bulk modulus is the volumetric stress / volumetric strain

The bulk modulus 'K' = E / [3(1-2 nu)] = 67.0 x 10^9 Pa

Volumetric stress is the applied pressure 'p' = 1.01 x 10^5 Pa

Volumetric strain = p / K = 1.5 x 10^-6 (the fractional change in volume)