Question

ii) A cylinder of radius 12 cm contains water up to the height of 20 cm A spherical iron ball is
dropped into the cylinder and thus water level raised by 6.75 cm. What is the radius of the v
ball ?​

Answer 1

Answer: Given radius of the cylinder, r = 12 cm

It is also given that a spherical iron ball is dropped into the cylinder and the water level raised by 6.75 cm

Hence volume of water displaced = volume of the iron ball

Height of the raised water level, h = 6.75 m

Volume of water displaced = πr2h

= π × 12 × 12 × 6.75 cm3

⇒ Volume of iron ball = π × 12 × 12 × 6.75 cm3 → (1)

But, volume of iron ball =

From (1) and (2) we get

⇒ r3 = 33

∴ r = 9

Thus the radius of the iron ball is 9 cm