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Buoyancy: Screencasts

Explains what the buoyant force is and the forces acting on a submerged object.

We suggest you list the important points in this screencast as a way to increase retention.

Explains the source of the buoyant force and how a force balance can be used to derive the buoyant force.

We suggest you list the important points in this screencast as a way to increase retention.

Important Equations:

Equation for the buoyany force of a submerged or partially-submerged object:

\[ F_b = \gamma_f * V_{body}\]

where \(F_b\) is the buoyant force, \(\gamma\) is the specific weight of the submerged fluid, and \(V_{body}\) is the volume of the object that is submerged. 

Archimedes’ principle can also be used to find the buoyant force:

\[F_b = m_{displaced} * g\]

where \(m_{displaced}\) is the mass of the submerging fluid displaced by the object and \(g\) is the acceleration due to gravity. 

If a completely-submerged object’s weight is greater than the buoyancy force, it will sink. If its weight is less than the buoyancy force, it will partially submerge until the buoyant force equals the object’s weight.