Question

a metal pipe is 77cm long. The inner diameter of a cross section is 4th. the outer diameter being 4.4cm find its inner curved surface area outer curved surface area and total surface area.

Answer 1

Answer :

-- INNER CURVED SURFACE AREA --

Given Length of metal pipe = 77 cm

Inner Diameter of metal pipe = 4 cm

Inner radius of pipe (r) = 4÷2 = 2 cm

Inner Curved Surface area = 2πrh

=>
$2 \times \frac{22}{7} \times 2 \times 77 \\ \\ 44 \times 22 \\ \\ 968 \: cm {}^{2}$

-- OUTER CURVED SURFACE AREA --

Outer diameter of pipe = 4.4 cm

Outer Radius of pipe (R) = 4.4 ÷ 2 = 2.2 cm

Outer Curved suface area = 2πRh

=>
$2 \times \frac{22}{7} \times 2.2 \times 77 \\ \\ 2 \times \frac{22}{7} \times \frac{22}{10} \times 77 \\ \\ \frac{22 \times 22 \times 11}{5} \\ \\ \frac{484 \times 11}{5} \\ \\ \frac{5324}{5} \\ \\ 1064.8 \: cm {}^{2}$

-- TOTAL SURFACE AREA --

There are 2 circles of radii 2cm and 2.2 cm at both the ends of pipe.

Therefore Area of 2 edges of pipe

=> 2(area of outer Circle - area of inner circle)

=> $2(\pi{R}^2 - \pi{r}^2)$

$2\pi(2.2 {}^{2} - {2}^{2} ) \\ \\ \frac{44}{7} \times 4.84 - 4 \\ \\ \frac{44}{7} \times 0.84 = 5.28 {cm}^{2}$

Total Surface area of pipe =

Inner curved surface area + outer curved surface area + Area of two edges

=> 968 + 1064.8 + 5.28

$= > \: 2038.08 \: {cm}^{2}$


$therefore \\ \\ inner \: curved \: surface \: area = 968 \: cm {}^{2} \\ \\ outer \: curved \: surface \: area \: = 1064.8 \: {cm}^{2} \\ \\ total \: surface \: area \: = \: 2038.08 \: {cm}^{2}$

HOPE IT WOULD HELP YOU

Answer 2

HEY MATE HERE IS YOUR ANSWER

$<b><i>$

Question :- A metal pipe

77 cm long the inner diameter of a cross section 4 cm the outer diameter being 4.4 cm find its

1.Inner C. S. A
2. Outer C. S. A
3. T. S. A

$<big >$

1. Inner CSA = 2 pie × r × h

Diameter = 4 cm

Radius :- 4/2 cm = 2cm

CSA = 2 × 22/7 × 2 × 77

➡️ 968 cm^2

2.

Outer CSA = 2 pie × r × h

Diameter :- 4.4 cm

Radius :- 4.4 / 2

➡️ 2.2 cm

CSA :- 2 × 22/7 × 2.2 × 77

CSA :- 1064.8 cm^2

3. TSA = 2 pie ( R + r) ^2

➡️ 2×22/7 × (2.2 + 2) (2.2 - 2)

➡️ 2× 22/7 × 4.2 × 0.2

➡️ 2 × 22/7 × 0.84

➡️ 2.64 cm^2

Area of two bases :- 2 × 2.64 = 5.28 cm^2

Total surface area of pipe :- inner CSA + outer CSA + area of two bases

= (968 + 1065 + 5.28) cm^2

➡️ 2038.08 cm^2

________________________

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Ansh as ans81