Mass Air Bubble: Negative Effects in Material Medium

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The discussion centers on the concept of negative mass for air bubbles in a material medium, primarily due to their buoyancy. When analyzing the forces acting on the bubble, the effective mass can be modified to reflect a negative value when considering the density of the surrounding fluid. This leads to the conclusion that the bubble exerts an upward force, which can be mathematically represented as a modification of gravitational effects. Instead of focusing on negative mass, it is often more practical to redefine effective gravity to account for the buoyant forces. This approach simplifies the computational analysis of bubbles in various materials.
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Why is the mass of air bubble in material medium considered to be negative?
 
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Himal kharel said:
Why is the mass of air bubble in material medium considered to be negative?

Please provide a link where this is used. Negative mass for a bubble would seem to be a clumsy computational tool.
 
Himal kharel said:
Why is the mass of air bubble in material medium considered to be negative?
Well, at first glance: the air bubble is going to be bouyant, so yeah, a self-contained discrete object (and no skin, like a balloon has) with, essentially, a negative mass. If the material is sensitive to strain, the bubble would push upward.
 
F=mg-\frac{m}{\rho_{air}}\rho_{water}g=<br /> (m(1-\frac{\rho_{water}}{\rho_{air}}))g<br />
so that the mass gets modified to:
m \rightarrow m(1-\frac{\rho_{water}}{\rho_{air}})
which can be negative?

I think what's more common is to define an effective gravity rather than an effective mass, and have:
g \rightarrow g(1-\frac{\rho_{water}}{\rho_{air}})
 

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