Does gamma equal density in Kg/m^3?

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The discussion clarifies the relationship between weight density (gamma) and mass density (rho) in fluid mechanics. It establishes that gamma is calculated using the formula γ = ρ ⋅ g, where ρ is the mass density in kg/m³ and g is the acceleration due to gravity (9.81 m/s²). The confusion arises from the units, as pressure (pgh) is expressed in N/m³, while mass density is in kg/m³. Therefore, to convert mass density to weight density, one must multiply by 9.81.

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Parsifal1
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I want to use the equation:

Fr='gamma'*distance from centroid*Area

but the example is showing density in N/m^3

while I only have the density in kg/m^3

Does this mean I have to multiply it by 9.81 to get the right answer?

Thanks.
 
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Parsifal1 said:
I want to use the equation:

Fr='gamma'*distance from centroid*Area

but the example is showing density in N/m^3

while I only have the density in kg/m^3

Does this mean I have to multiply it by 9.81 to get the right answer?

Thanks.
γ is known as the 'weight density' of a substance. γ = ρ ⋅ g, where ρ is the mass density and g is the acceleration due to gravity.
 
SteamKing said:
γ is known as the 'weight density' of a substance. γ = ρ ⋅ g, where ρ is the mass density and g is the acceleration due to gravity.
So, pgh is expressed in N/m^3 as opposed to Kg/m^3?
 
Parsifal1 said:
So, pgh is expressed in N/m^3 as opposed to Kg/m^3?
No. Re-read Post #2 again carefully and then work out the units of ρgh versus just ρg.
 

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