Question

A metal pipe is 77 cm long. The inner diameter of a cross
section is 4 cm, the outer diameter being 4.4 cm
(see Fig. 13.11). Find its
(1) inner curved surface area,
(ii) outer curved surface area,
(iii) total surface area.​

Answer 1

Step-by-step explanation:

(formulas used -curved surface area of cylinder2πrh

-total surface area:2πr(r+h))

1) given.length(height)=4cm

inner diameter 4cm

so, radius 4/2=2cm

inner curved surface area

2πrh

2×22/7×2×77cm

968cm^2

2)given length (height)=77cm

outer diameter=4.4cm

so,radius 4.4/2=2.2cm

2πrh

2×22/7×2.2×77cm

44×2.2×77cm

1064.8cm^2

3) total surface area-2πr^2h=2π(R^2-r^2)h

Area 1+Area 2+2π(R1^2-r2^2)

2πrh+2πrh+2π(R^2-r^2)

(968+1064.8+2π{(2.2^2)-(2^2)})cm^2

(2032.8+2×22/7×0.84)cm^2

(2032.8+5.28)cm^2

2038.08cm^2 answer

hopes it's help you...

*