Question

A metallic pipe whose external and internal diameter are 9cmand 7cm, has a length of 2.8m. Find the volume of the metal.​

Answer 1

Answer:

$\bigstar{\bold{Volume\:of\:metal=7040\:cm^{3}}}$

Step-by-step explanation:

$\Large{\underline{\rm{Given:}}}$

• External diameter = 9 cm
• Internal diameter = 7 cm
• Height of the pipe = 2.8 m = 280 cm

$\Large{\underline{\rm{To\:Find:}}}$

• Volume of the metal

$\Large{\underline{\rm{Solution:}}}$

➔ First we have to find the outer and inner volumes of the metal

➔ Here we know that the pipe is in the form of a cylinder.

➔ Volume of a cylinder is given by,

    Volume of a cylinder = π r² h

➔ Substitute the data,

    Outer volume of the pipe = 22/7 × 9/2 × 9/2 × 280

    Outer volume of the pipe = 11 × 9 × 9 × 20

    Outer volume of the pipe = 17820 cm³

➔ Hence outer volume of the pipe is 17280 cm³.

➔ Now we have to find the inner volume of the pipe.

    Inner volume of pipe = 22/7 × 7/2 × 7/2 × 280

    Inner volume of pipe = 11 × 7 × 140

    Inner volume of pipe = 10780

➔ Hence inner volume of the pipe is 10780 cm³.

➔ Now the volume of the pipe is given by,

    Volume of the pipe = Outer volume - Inner volume

    Volume of the pipe = 17820 - 10780

    Volume of the pipe = 7040 cm³

➔ Hence volume of the metal used is 7040 cm³.

     $\boxed{\bold{Volume\:of\:metal=7040\:cm^{3}}}$