Question

metal pipe is 77 cm long the inner diameter of the cross is section is 4 cm and thickness of metal is 0.2cm then outer surface area is​

Answer 1

Answer:

968 cm

Step-by-step explanation:

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Answer 2

$\huge\boxed{\fcolorbox{black}{yellow}{QUESTION:-}}$

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

(i) inner curved surface area,

(ii) outer curved surface area,

(iii) total surface area.

$\huge\boxed{\fcolorbox{black}{yellow}{ANSWER:-}}$

GIVEN :-

Length = 77 Cm.

Inner Diameter = 4 Cm.

Thickness = 0.2 Cm.

TO FIND :-

(i) inner curved surface area,

(ii) outer curved surface area,

(iii) total surface area.

SOLUTION :-

(i) inner curved surface area

According to the question inner diameter is 4 cm,

then,

Inner radius of a cylindrical pipe = r1

= Innner diameter/2

= (4/2)cm

= 2cm

Height (h) of cylindrical pipe = 77 cm,

Curved Surface Area of inner surface of pipe  =2πr1h

= (2×22/7×2.2×77)cm²

= 968cm²

(ii) Outer curved surface area

According to the question outer diameter is 4.4 cm

Outer radius of cylindrical pipe = r2

= Outer diamter/2=(4.4/2)cm=2.2cm

Height of cylinder

=> h = 77 cm,

Curved area of outer surface of pipe

= 2πr2h

= (2×22/7×2.2×77)cm²

= (2×22×2.2×11)cm2

= 1064.8cm²

(iii) Total surface area

Total surface area = curved surface area of inner cylinder + curved surface of outer cylinder + 2 × Area of base.

Area of base = area of circle with radius 2.2 cm - Area of circle with radius 2 cm

= πr2²−πr1²

= 7

= 22/7×((2.2)²−(2)²)

= 22/7×(4.84−4)

= 22/7×(0.84)

= 2.74cm²

Total surface area = curved surface area of inner cylinder + curved surface area of outer cylinder + 2 × Area of base.

= 968+1064.8+2×2.74

= 2032.8 + 5.76

= 2039.08cm²

Therefore, the total surface area of the cylindrical pipe is 

= 2039.08cm²