Why weight of steel bar is D2/162
Since we know weight of a steel bar per meter length in kg is W = D²/162 Where W is the weight of steel bar and D is the dia of bar Cross sectional area of steel bar = ∏r² [D=2r , r=D/2] = ∏D²/4 Vol of steel bar per meter length = ∏D²/4 x 1000 Density of steel = 7850 kg/m³ = 7850 kg/1000 x 1000 x 1000 Now weight of bar per meter = vol of steel bar x Density of steel = ∏D²/4 x 1000 x 7850 kg/1000 x 1000 x 1000 = 3.14 D²/4 x 7850 x 1000 x 1000 = 0.785 D² x 0.007850 = 0.00616225 x D² = 0.00616225 / 1 x D² / 1 = D²/1/0.00616225 = D²/162.28
