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


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