Question

The volume of one metre iron rod is 1386m3 find its diameter

Answer 1

Volume = 3850 cm3 Length i.e. height = 1 m = 100 cm Volume = πr2h 22/7 x r2 x 100 = 3850 r2 = 3850/100 x 7/22 r2 = 12.25 r = √12.25 r = 3.5 So, the diameter of the rod is 2 x 3.5 i.e. 7 cm.

Answer 2

Ans:

Given , length (height) of iron rod =1m

And volume =1386 m3

We have,

Volume of cylinder = pie × r × r × h

1386 =22/7×1×r×r

1386×7/22 = r×r

r×r=63

So r= root 63 or 7.93 (approximate)