Question

A metallic pipe whose external and internal diameters are 9 cm and 7 cm,has a length of 2.8 m . Find the volumn of metal.

Answer 1

External diameter=9cm,R=9/2
Internal diameter=7cm,r=7/2
height=2.8m=280cm
then a/q

volume of metal=πRsq.h-πrsq.h
=πh(Rsq-rsq)
=(22/7)×280{(9/2)sq-(7/2)sq}
=22×40(81/4-49/4)
=880×32/4
=880×8
=7040cmsq