A cylindrical road roller made of iron is 1 m long. Its internal diame

1.	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 (use π = 3.14)
Answer» Given that, internal radius of cylinder road roller (r1) = \(\frac{54}2\) = 27 cm 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) = 1 m 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

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 (use π = 3.14)

Answer»

Given that,

internal radius of cylinder road roller (r1) = \(\frac{54}2\) = 27 cm

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) = 1 m

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