Question

A metal pipe is 28 cm long and has an external radius of 2.1 cm. If its thickness is 0.7 cm, then find the whole surface area of the pipe.

Answer 1

given that,

external diameter = 8 cm

external radius = R =4 cm

thickness= 1 cm

so, internal diameter= (8-1) cm = 7 cm

internal radius = r = 3.5 cm

volume of iron = π(R²- r²)h

=> 247.5 cm³

weight of iron = 247.5× 8 = 1980 gram or 1.98 kg

Answer 2

Answer:

2457.5cm^3

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