- #1

- 2

- 0

## Homework Statement

Hollow iron sphere is half submerged in water.Sphere has outer diameter of 10 cm. Calculate thickness of the wall , when the iron density is 7.9 g / m3.

I get answer 0.11cm, book says that it is 0.22cm.

## Homework Equations

[/B]

## The Attempt at a Solution

*First i found*buoyant force F=

**ρ**gV/2 where

**ρ**is density of water and V is volume of a sphere.

Then I found mass of a sphere :

**ρ**gV/2=mg

m=0.26 kg

I know density of iron ,so: 7900=0.26/v where v is volume of the wall

(v= volume of outside sphere - volume of inside sphere.)

From there I get thikness of the wall to be 0.11cm.