Question

Plzzz solve the problem..... ​

Answer 1

GIVEN : -

• External radii of a hollow cylindrical pipe = 8 cm.
• Internal radii of a hollow cylindrical pipe = 6 cm.
• Length = 35 cm is melted.
• Thickness of a solid wire = 2.8 cm, Radius = $\sf \dfrac {2.8}{2} \ = \ 1.9 \ cm$

TO FIND :-

• The length of the wire = ?

SOLUTION :-

• To find the length of the wire.
• Volume of cylinder = volume of wire.

$\large \red {\underline {\boxed {\sf Volume \ of \ cylinder \ = \ \pi (R^2 \ - \ r^2) \times h}}}$

Put the given values in the above formula, :-

:$\implies \sf \dfrac {22}{7} \times (8^2 - 6^2) \times 35$

:$\implies \sf \dfrac {22}{7} \times (64 - 36) \times 35$

:$\implies \sf \dfrac {22}{7} \times 28 \times 35$

:$\implies \sf 22 \times 5 \times 28$

:$\implies \sf 110 \times 28$

$\therefore$ Volume of cylinder = 3080 cm³.

Now,

Volume of cylinder = volume of wire = 3080 cm³.

$\sf Volume \ of \ wire \ = \ \pi r^2 l$

:$\implies \sf 3080 \ = \ \dfrac {22}{7} \times 1.9 \times l$

:$\implies \sf \dfrac {(3080 \times 7)}{(22 \times 1.9)} \ = \ l$

$\qquad \large \red {\underline {\boxed {\sf l \ = \ 515.78 \ cm}}}$

$\therefore$ The length of the wire is 515.78 cm.

Answer 2

Given diameter of the cylinder as 20 cm, so the radius of the cylinder is 10 cm(since, diameter is twice the radius).

Height/Length of the cylinder is given as 20 cm

Volume of the cylinder is =π×r^2×h

So volume=π×(10)^2×20 cubic centimeter

Volume = 6283.18 cm^3

Or converting in terms of metres..

Volume=6.28318×10^(-3) m^3

Hope it's helpful to you