Question

The volume of a 1m long iron rod is 1386.Find it diameter

Answer 1

Answer:

41.6 m

Step-by-step explanation:

$\text{Height of cylinder = 1 m}\\\\\text{Let height be h.}\\\\\text{Then, vol = } \pi r^2 h\\\\\text{But, given vol = 1368 m}^3\\\\\therefore \: \: \pi r^2 h = 1368\\\\\implies \dfrac{22}{7} \times r^2 \times 1 = 1368\\\\\\\implies r^2 = \dfrac{1368 \times 7}{22} = 435.27\\\\\\\implies r = \sqrt{435.27} = \boxed{20.8 \: m}\\\\\text{Diameter = 2(20.8) = 41.6 \: m}$

Hope it helps!

Answer 2

Answer:

42 m

Step-by-step explanation:

Volume = πr²h

Find the radius:

πr²(1) = 1386

πr² = 1386

r² = 1386 ÷ π

r² = 441

r = √441

r = 21 m

Find the diameter:

Diameter = 2 x radius

Diameter = 2 x 21 = 42 m

Answer: 42 m