Question

a metallic pipe is 0.5 cm thick . It's inner radius is 4.5 cm and length 5 cm . Find its total surface area​

Answer 1

Answer:

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Explanation:

Inner radius = 3.5 cm and outer radius = 4.2 cm

Length = 5 dm = 50 cm

Surface area of inside of pipe = (circumference)(length) = 2π(3.5 cm)(50 cm)

= 350π cm2

Surface area of outside of pipe = 2π(4.2 cm)(50 cm) = 420π cm2

Surface area of each end of pipe = outer area - inner area

= π(4.2 cm)2 - π(3.5 cm)2 = 5.39π cm2

Total surface area = 2(5.39π) cm2 + 350π cm2 + 420π cm2 = 775.39π cm2