What is the volume of the iron required to make a 70 cm long rod of 2.1 cm diameter?

Let the base radius be ‘r’ and length be ‘l’ and diameter be ‘d’ of the cylinder rod

Volume of the iron required is equal to volume of the rod

⇒ Given that d= 2.1cm

∴ r = 1.05cm

and l = 70cm

⇒ Volume of cylinder V= Area of circle at bottom × height

Volume of iron required

Ans. 242.55 cu cm