Question

a metal pipe has a bore (inner daimetre) of 5cm. The pipe is 5mm thick all around. Find the weight, in kilogram, of 2metre of pipe if 1 cm^3 of a metal 7.7g

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Answer 1

Answer:

13310 g.

Step-by-step explanation:

Inner radius(r₂) = 5/2 = 2.5 cm.

Thickness = 0.5cm all around. So, outer radius(r₁) = 2.5 + 0.5 = 3cm.

Now, Volume of Cylinder = πr²h. { Here, h = 2m = 200cm}

Required volume = outer volume - inner volume

                             = π(r₁)²h - π(r₂)²h

                             = πh { (r₁)² - (r₂)² }

                             = πh { 3² - (2.5)² }

                             = πh ( 2.75 ) = (22/7)*200*(2.75)

                              = 12100/7 cm³

Now, 1 cm³ = 7.7g

  So, 12100/7 cm³  = (12100/7)* 7.7 g

     Weight = 13310 g = 13.310kg