Surface force

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Surface force denoted fs is the force that acts across an internal or external surface element in a material body. Surface force can be decomposed into 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[edit]

Surface force due to pressure[edit]

 f_s=p \cdot A  \

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

Examples[edit]

Pressure related surface force[edit]

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

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

 5 \mathrm{Pa} \cdot 20 \mathrm{m^2} = 100 \mathrm{N}

See also[edit]