# Buoyancy

Written by Jerry Ratzlaff on . Posted in Fluid Dynamics

Buoyancy, abbreviated as B, is when a liquid applies upward force on an object that is completely submerged or floating.

## Buoyancy Types

• Positive buoyancy - when the liquid force is greater than the object weight displacement.
• Negative buoyancy - when the liquid force is less than the object weight displacement.
• Neutral buoyancy - when the liquid force is equal to the object weight displacement.

## Buoyancy formulas

 $$\large{ B = p \;A }$$ $$\large{ B = \rho\; V\; g }$$ $$\large{ B = \rho \;g \;h\; A }$$

### Where:

$$\large{ B }$$ = buoyancy force

$$\large{ V }$$ = displaced volume

$$\large{ \rho }$$ (Gtrrk symbol rho) = fluid density

$$\large{ g }$$ = gravitational acceleration

$$\large{ h }$$ = height of liquid displaced by a floating object

$$\large{ p }$$ = pressure

$$\large{ A }$$ = surface area of object