A cylindrical road roller made of iron is 1 m long. Its internal diameter is 54 cm and the thickness of the iron sheet used in making the roller is 9 cm. find the mass of the roller, if 1 cm3 of iron has 7.8 gm mass
Given that, internal radius of cylinder road roller (r1) = = 27cm
Thickness of road roller (t) =9 cm
Radius of cylinder road roller be R
t = R –r
t = R-27
R = 9 + 27 = 36 cm
Given height of cylindrical road roller (h) =1m
h = 100 cm
Volume of iron=πh(R2-r2)
= π(362 - 272) × 100
= 1780.38 cm
Mass of 1 cm of iron = 7.8 gm
Mass of 1780.38 cm of iron = 1780.38 × 7.8
=1388696.4 gm
∴ Mass of roller (m) = 1388.7 kg