Question -
Answer -
Let the length of thepipe be h cm.
Then, Volume of cuboid= (53 x 40 x 15) cm3
Internal radius of thepipe = 7/2 cm = r
External radius of thepipe = 8/2 = 4 cm = R
So, the volume of ironin the pipe = (External Volume) – (Internal Volume)
= πR2h – πr2h
= πh(R2– r2)
= πh(R – r) (R + r)
= π(4 – 7/2) (4 + 7/2)x h
= π(1/2) (15/2) x h
Then from the questionit’s understood that,
The volume of iron inthe pipe = volume of iron in cuboid
π(1/2) (15/2) x h = 53x 40 x 15
h = (53 x 40 x 15 x7/22 x 2/15 x 2) cm
h = 2698 cm
Therefore, the lengthof the pipe is 2698 cm.