Question

a) An iron pipe of internal diameter 2.8 cm and uniform thickness 1 mm is melted and a solid cylindrical rod of the same length is formed. Find the diameter of the rod.

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Answer 1

Answer:

The cross-section of the pipe has area

pi/4 (2.9^2-2.8^2) = 0.1425pi cm^2

The rod of radius r has area

pi r^2 cm^2

So, pi r^2 = 0.1425 pi

r=0.3775 cm

So, the diameter is 0.755 cm

hope it helps