Question

A cylinder of radius 12 cm contains water to a depth of 20 cm. A spherical iron ball is dropped into the cylinder and thus the level of water is raised by 6.75 cm. Find the radius of the ball.
(Use 𝜋 = 22/7).

Answer 1

Given that,
Radius of cylinder= 12cm =`r_1` 
Raised in height =6.75cm=h 

⇒ Volume of water raised = Volume of the sphere

⇒ `πr_1^2h=4/3πr_2^3`

⇒ `(12xx12xx6.75)=4/3r_2^3`

⇒`(12xx12xx6.75xx3)/4=r_2^3`

⇒`r_2^3=729`

⇒`r_2=9cm`

Radius of sphere is 9cm.