## Buoyant Formula :

Buoyant Formula is force acting F_{b(N)} in Newton is equal to the Force acting up wards F_{2(N)} in Newton and minus the force acting downwards F_{1(N)} in Newton. Buoyant Formula can be written as

**F _{b(N)}=F_{2(N)}-F_{1(N)}**

Where,

F→ force acting in Newton

F2→ force acting upwards

F1→ force acting downwards

**Force, F=PA**

Where,

P→ pressure and

A→ Area

##### In terms of Area Height and volume, it is given by,

**F _{b}=h_{2}pg-h_{1}pg**

Where,

P→ density of the fluid is p

g → gravity in Newton/Kg^{-1}

V → volume of the immersed part of the body in the fluid in SI unit cube meter m^{3}

h→ height of the immersed part in cm

A→ area in m^{2}

## Sample Problems :

### Example 1:

A block of wood with length =3.5m, width=0.3 and height=0.8m. The density of water

1000kg/m^{3 } If the block is placed in the water, when is the buoyant force. Acceleration due to gravity is 20N/kg

### Solution :

Known,

Volume of the block V=length*width*height=3.5*0. *0.8=0.84m^{3}

Density of water (p)=1000kg/m^{3}

Acceleration due gravity (g)=20N/kg

Formula of buoyant force

F=(1000)(20)(0.84)

F=16800Newton

### Example 2:

A block of wood with length =4.5m, width=0.8 and height=10m. The density of water

100kg/m^{3 } If the block is placed in the water, when is the buoyant force. Acceleration due to gravity is 10N/kg

### Solution :

Known,

Volume of the block V=length*width*height=4.5*0.8*10=36m^{3}

Density of water (p)=100kg/m^{3}

Acceleration due gravity (g)=10N/kg

Formula of buoyant force

F=(100)(10)(36)

F=36000Newton