Q. 214.1( 20 Votes )

# The length of a metallic tube is 1 metre, its thickness is 1 cm and its inner diameter is 12 cm. Find the weight of the tube if the density of the metal is 7.7 grams per cubic centimetre.

Hint. Weight of 1 cm^{3} of metal = 7.7 g.

Answer :

It is given in the question that,

_{Length = 1m}

_{= 100cm}

_{Inner diameter = 12 cm}

_{Inner Radius = 6 cm}

_{Hence,}

_{Inner volume} =Πr_{1}^{2}h

Thickness = 1 cm

outer radius = 7 cm

Now,

We can calculate the following measurements:

Total volume =Πr_{2}^{2}h

Now,

Volume of the tube = total volume – inner volume

= Πr_{2}^{2}h- Πr_{1}^{2}h

= Πh(r_{2}^{2} - r_{1}^{2})

= 3.14 × 100 × (7^{2} - 6^{2})

= 3.14 × 100 × (49 - 36)

= 314 × 13

= 4082 cm^{3}

We have,

Density of the tube = 7.7 g/cm^{3}

Therefore,

Weight of the tube = volume × density

= 4082 × 7.7

= 31431g

= 31.43 kg

Rate this question :

A rectangular strip 25 cm× 7 cm is rotated about the longer side. Find the volume of the solid, thus generated.

RD Sharma - MathematicsFill in the blanks to make the correct statement.

Two cylinders of equal volume have heights in the ratio 1:9. The ratio of their radii is ________.

NCERT - Mathematics ExemplarThe radii of two cylinders are in the ratio 2 : 3 and their heights are in the ratio 5 : 3. Calculate the ratio of their volumes.

RD Sharma - MathematicsThe ratio between the curved surface area dna the total surface area of a right circular cylinder is 1 : 2. Find the volume of the cylinder, if its total surface area os 616 cm^{2}.

The height of a right circular cylinder is 10/5 m. Three times the sum of the areas of its two circular faces is twice the area of the curved surface. Find the volume of the cylinder.

RD Sharma - MathematicsFrom a tap of inner radius 0.75 cm, water flows at the rate of 7 m per second. Find the volume in litres of water delivered by the pipe in one hour.

RD Sharma - MathematicsHow many cubic metres of earth must be dug-out to sink a well 21 m deep and 6 mdiameter?

RD Sharma - Mathematics