If a spherical metal bob of radius 3cm is fully... - JAMB Physics 2001 Question

If the bob is fully immersed in the water, then the volume of water displaced will be equal to the volume of the bob = 4/3πr³, where r is the radius of the bob.

This volume of water in the cylinder = πr²l, where r = radius of the cylinder, and l = level of water rose in the cylinder.

Therefore, π x r² x l = 4/3 x π x 3³

Then r² = 36

r = √36

r = 6cm