Buoyancy & Buoyant Force Video Lessons

Concept

# Problem: A fat slab of styrofoam, with a density of 32 kg/m3 floats on a lake. What minimum volume must the slab have so that a 40 kg boy can sit on the slab without sinking?

###### FREE Expert Solution

From Archimede's principle, the buoyant force is:

$\overline{){{\mathbf{F}}}_{{\mathbf{B}}}{\mathbf{=}}{{\mathbf{\rho }}}_{{\mathbf{r}}}{\mathbf{g}}{{\mathbf{V}}}_{{\mathbf{f}}}}$

The buoyant force, FB = Ws + Wb

###### Problem Details

A fat slab of styrofoam, with a density of 32 kg/m3 floats on a lake. What minimum volume must the slab have so that a 40 kg boy can sit on the slab without sinking?