Find the distance by which a 42cm diameter, 9.4m tall concrete column is compressed when it supports a 12900kg load

Answer 1

Young’s Modulus E=17•10⁹ N/m²
σ=Eε
mg/A=E(ΔL/L)
ΔL= mgL/AE= 4mgL/ πD²E=
=4•12900•9.8•9.4/π•0.42²•17•10⁹=
=5•10⁻⁴ m=0.5 mm.