Question

m thick. Inner radius of the pipe is 3.5 cm and length is
6. A metallic pipe is 0.7 cm thick. Inn
5 dm. Find its total surface area.
[Hint: Total surface area = Inner surfac
Inner surface area + Outer surface area + Area of two rimel

Answer 1

Correct Question :-

A metallic pipe is 0.7 cm thick .Inner radius of the pipe is 3.5 cm and length is 5 Dm.Find it's total surface area ?

Given :-

Thickness of pipe = 0.7 cm

Inner radius (r) = 3.5 cm

Outer radius (R) = 3.5 + 0.7 = 4.2 cm

Length(h) = 5 dm = 50 cm

To Find :- TSA of metallic pipe

Solution :-

TSA = Inner surface area + outer surface area + area of two rims

= 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 cm^2

Therefore, the total surface area of a metallic pipe is 2453.88 cm^2.

Answer 2

Question (corrected) :

A metallic pipe is 0.7 cm thick .Inner radius of the pipe is 3.5 cm and length is 5 dm. Find it's total surface area ?

Given,

Length of the given pipe  =  5 dm = 5 cm.

Inner radius of the pipe (r) = 3.5 cm

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

Thickness of pipe = 0.7 cm

Thus,

Total Surface Area (T.S.A ) =

Inner surface area + Outer surface area + Area of two rimes

=  2π(r + R) (h + R - r)  

On putting the values,

= $2*\frac{22}{7}(3.5+4.2)(50+4.2-3.5)$

= $2453.88cm^{2}$

Thus the total surface area of the given pipe is $2453.88cm^{2}$