# You place a block of wood into a beaker of water and it floats. What can you say about the buoyant force on the block?

Apr 26, 2016

The buoyant force is stronger than the gravity force (the block's weight). Consequently, the block's density is smaller than water's density.

#### Explanation:

Archimedes principle affirms that a body submerged in a fluid (for example a liquid, or more precisely, water) experiences an upward force equal to the weight of fluid (liquid, water) displaced.

Mathematically,

buoyant force $= {F}_{b} = {V}_{b} \cdot {d}_{w} \cdot g$
${V}_{b} =$ body volume
${d}_{w} =$ water density
$g =$ gravity acceleration

while the weight $W = {V}_{b} \cdot {d}_{b} \cdot g$

${d}_{b} = b o \mathrm{dy} \mathrm{de} n s i t y$

As the body floats $\implies {F}_{b} > W \implies {d}_{w} > {d}_{b}$