Surface force

Surface force denoted f_s is the force that acts across an internal or external surface element in a material body. Surface force can be decomposed in to two perpendicular components: pressure and stress forces.Pressure force acts normally over an area and stress force acts tangentially over an area.

Equations for surface force

Surface force due to pressure

: $f\_s=p\; cdot\; A$

f = Force p = pressure A = cross sectional area of the moving fluid

Examples

Pressure related surface force

Pressure is in $frac\{force\}\{area\}=frac\{N\}\{m^2\}$ Area is a $(length)cdot(width)\; =\; m\; cdot\; m\; =\; m^2$

Given a pressure of $5\; frac\{N\}\{m^2\}\; =\; 5\; pascals$ and an area of $20\; m^2$ find the surface force due to pressure.

:$5\; Pa\; cdot\; 20\; m^2\; =\; 100\; N$

See also

*Body force