Question

find the weight of the hollow cylinder whose outer diameter is 70 mm, inner diameter is 35mm and length is 150mm. take a density of mild steel as 7.8 gms/cm cube

Answer 1

Volume of hollow cylinder = pi h ( R^2 - r^2) = 22/7 x 150( 70^2 - 35^2) = 22/7x 150 x ( 4900 - 1225) = 22/7x 150 x 3675 = 22 x150 x 525= 1732800 square mm = 17328 square cm now weight = volume x density = 17328x 7.8 gms = 135158.4 gms = 135.1584 kg