Question

A metal pipe is 77cm long ,the inner diameter of the cross - section is 4 cm and the outer diameter is 4.8 cm . Find the (i) inner curved surface area (ii) outer curved surface area (iii) total surface area

Answer 1

Hope this helps u....

Answer 2

Answer:

i) $I=968 cm^2$

ii) $O=1161.6 cm^2$

iii) $T=2140.6528 cm^2$

Step-by-step explanation:

Given : A metal pipe is 77cm long ,the inner diameter of the cross - section is 4 cm and the outer diameter is 4.8 cm.

To find : (i) inner curved surface area

(ii) outer curved surface area

(iii) total surface area

Solution :

Height of the metal pipe = 77 cm

Inner diameter d=4 cm ⇒ r=2 cm

Outer diameter D=4.8 cm ⇒ R=2.4 cm

(i) Inner curved surface area

$I=2\pi rh$

$I=2(\frac{22}{7})(2)(77)$

$I=4\times 22\times 11$

$I=968 cm^2$

(ii) Outer curved surface area

$O=2\pi Rh$

$O=2(\frac{22}{7})(2.4)(77)$

$O=4.8\times 22\times 11$

$O=1161.6 cm^2$

(iii) Total surface area

$T=I+O+2\pi(R^2-r^2)$

$T=968+1161.6+2(3.14)(2.4^2-2^2)$

$T=2129.6+2(3.14)(1.76)$

$T=2129.6+11.0528$

$T=2140.6528 cm^2$