Question

A cylindrical tub of radius 16 cm contains water to a depth of 30 cm. A spherical iron ball is dropped into the tub and thus level of water is raised by 9 cm. What is the radius of the ball?

Answer 1

Let r be the radius of the iron ball
Then, Volume of iron ball = Volume of water raised in the hub

⇒`4/3πr^3=πr^2h`

⇒`4/3r^3=(16)^2xx9`

⇒`r^3=(27xx16xx16)/4`

⇒ `r^3=1728`

⇒ r=12cm

Therefore, radius of the ball = 12cm.