Question

A metal pipe is 77 m long. The inner diameter of a cross section is 4 cm the outer diameter 4.4 cm. Find its
i) Inner curved area
ii) outer curved area
iii) Total surface area
iv) Volume of metal
Hint: Total surface area= Inner CSA + Outer CSA + 2* Area of base )
and area of base=22/7R Sq. - 22/7r Sq.

Answer 1

Answer:

There is a inner Cylinder and Outer Cylinder. Inner Surface area of the Pipe = 2∏rh = 2*22*2*77/7 = 968 Square cm. Outer Surface area of the pipe = 2∏Rh = 2*22*2.2*77/7 = 1064.8 Square cm.

pls, Mark as BRAINLIEST plsssssssss0

Answer 2

Given:-

• Length of metal pipe = 77 metre
• The inner diameter of a cross section = 4 cm
• The outer diameter of a cross section = 4.4cm

To find:-

• i) Inner curved area
• ii) outer curved area
• iii) Total surface area
• iv) Volume of metal

Solution:-

• Inner radius (r) = $\sf \dfrac{4}{2}$ = 2cm

• Outer radius (R) = $\sf \dfrac{4.4}{2}$ = 2.2cm

• Height of Pipe (h) = 77 cm

$\underline {\rule{261}{2}}$

★ Inner surface area of the pipe:-

$\dashrightarrow\sf 2 \pi rh \\ \\ \dashrightarrow\sf 2 \times \frac{22}{ \cancel{7}} \times 2 \times \cancel{77} \\ \\ \dashrightarrow\bf \red{968 cm^2}$

$\rule{200}3$

★ Outer surface area of the pipe:-

$\dashrightarrow\sf 2 \pi Rh \\ \\ \dashrightarrow\sf 2 \times \frac{22}{ \cancel{7}} \times 2.2 \times \cancel{77} \\ \\ \dashrightarrow\bf \red{1064.8 cm^2}$

$\rule{200}3$

★ Total Surface Area:-

= Inner surface area + Outer surface area + 2( Area of cross section)

$\dashrightarrow\sf 968 + 1064.8 + 2 \pi (R^2 - r^2) \\ \\ \dashrightarrow\sf 2032.8 + 2 \times \frac{22}{7} \bigg( (2.2)^2 - (2)^2 \bigg) \\ \\ \dashrightarrow\sf 2032.8 + 5.28 \\ \\ \dashrightarrow\bf \red{2038.08 cm^2}$

$\rule{200}3$

★ Volume of metal:-

= Volume of outer pipe - Volume of inner pipe

$\dashrightarrow\sf \pi R^2 h - \pi r^2 h \\ \\ \dashrightarrow\sf \pi h( R^2 - r^2) \\ \\ \dashrightarrow\sf \frac{22}{7} \times 77 \bigg( (2.2)^2 - (2)^2 \bigg) \\ \\ \dashrightarrow\sf \frac{22}{ \cancel{7}} \times \cancel{77} ( 4.84 - 4) \\ \\ \dashrightarrow\sf 154 \times 0.84 \\ \\ \dashrightarrow\bf \red{129.36 cm^3}$

$\underline {\rule{261}{2}}$