Solving a Hydrostatic Problem: Cylinder Height in Water and Oil

[brykz]

Homework Statement

A Cylinder got ratio of 15 cm, and h=15. Their mass=7kg. This is floating in water. After we put oil on it (density=725kg/m^3), on the water.
Calculate what's the height of cylinder when its in oil.


Answer=7.6cm

Homework Equations

F=D x V x g

The Attempt at a Solution

I tried everything


Help please...

Sorry for my english.

 

[Shooting Star]

Hi, welcome to PF.

A Cylinder got ratio of 15 cm,

I think you mean "radius"...

So now that you know the volume and the height, and also the mass, you can calculate the density.

Homework Equations

F=D x V x g

F is the weight of the cylinder. Now it is surrounded by oil, which is exerting a buoyant force on it.

The Attempt at a Solution

I tried everything

Did you try Archimedes' principle? Do that now.