Question

A metallic pipe is 0.7cm thick.inner radius of the pipe is 3.5 cm and length is 5 dm.find its total surface area

Answer 1

Hello!

• Length = 50 cm

• Thickness of the pipe = 0.7cm

• Inner radius of the pipe (r)= 3.5cm

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

Total surface area of pipe :

= 2π (r + R ) (h + R - r)

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

= 44 / 7 × 7.7 × 50.7 = 2453. 88 cm²

Cheers!

Answer 2

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= 2x22/7(3.5+4.2)(50+4.2-3.5)


= 44/7 x 7.7 x 50.7


=2453.88cm^2


So the answer should be 2453.88cm^2