Question

A metallic pipe is 0.7. cm thick. Inner radius of the pipe is 3.5 cm and length is
5 dm. Find its total surface area.
Hint: Total surface area = Inner surface area + Outer surface area + Area of two rims​

Answer 1

Answer:

Step-by-step explanation:

Thickness of the pipe = 0.7cm

inner radius of the pipe (r )= 3.5cm

External radius of the pipe (R ) = (3.5+ 0.7 )cmor,4.2cm

length=5dm or,50cm

We know,

Total surface area of pipe = 2π (r+ R ) ( h+ R - r)

or, Total surface area of pipe= 2×22/7(3.5+4.2)(50+4.2-3.5)

= 44/7 × 7.7 × 50.7

=2453.88cm^2

So the answer should be 2453.88cm^2

Answer 2

Step-by-step explanation:

Thickness of pipe = h = 0.7 cm

Inner radius = r = 3.5 cm

External Radius = R = r + h = 3.5 + 0.7 = 4.2 cm

Length = 5 dm = 50 cm

Total surface area of cylinder or pipe = 2∏(r + R) (h + R - r)

= 2 × 22/7 × (3.5 + 4.2) (50 + 4.2 - 3.5)

= 2453.88 cm Sqaure