Question

The volume of a metallic cylinderical pipe is 748 cm.
it's length is 14 cm and its external radius is 9cm.find its thickness

Answer 1

The volume of a pipe is given by V = (pi)h(Ro^2-Ri^2). Here we have

748 = (pi)h(Ro^2-Ri^2), or

(22/7)*14*(9^2-Ri^2), or

(9^2-Ri^2) = (748*7)/(22*14) = 17, or

Ri^2 = 81–17 = 64, or

Ri = 8 cm

So the thickness of the pipe wall is 1 cm.