Question

The Volume of a 1-Metre iron rod is 1386 cu. CM. Find its Diametre

Answer 1

volume of a cylinder =πr^2h

1386=22/7*r^2*1

1386*7/22=r^2

63*7=r^2

441=r^2

taking square root

21=r

the radius of rod is 21 m

diameter is twice the radius

d=2r

=2*21

42m

therefore diameter of the rod is 42 metre