Question

The volume of a 1-metre iron rod is 1386 cu. cm Find its diameter

Answer 1

Solution:-
Given : Volume of rod = 1386 cu cm and height = 1 m or 100 cm
Volume of rod (iron rod is in the shape of cylinder) = πr²h
1386 = 22/7*r²*100
⇒ r² = (1386*7)/2200
⇒ r² = 9702/2200
⇒ r² = 4.41
⇒ r = √4.41
⇒ r = 2.1 cm
Diameter = 2.1 ×2 
Diameter = 4.2 cm
Answer.

Answer 2

Solution:-

Given : Volume of rod = 1386 cu cm and height = 1 m or 100 cm

Volume of rod (iron rod is in the shape of cylinder) = πr²h

1386 = 22/7*r²*100

⇒ r² = (1386*7)/2200

⇒ r² = 9702/2200

⇒ r² = 4.41

⇒ r = √4.41

⇒ r = 2.1 cm

Diameter = 2.1 ×2 

Diameter = 4.2 cm

Answer.