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.


HINT: Total surface area=Inner surface area+Outer surface area+Area of two rims.​

Answer 1

Answer:

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

Answer 2

May this image helps you