Suppose I were to take some object that will have a mass that is equal to that of water and I put it in water, will it submerge or float assuming that the object is solid?
$\begingroup$
$\endgroup$
2
-
1$\begingroup$ I'm no physicist, but I assume you mean density not mass? $\endgroup$– GarethCommented Jul 25, 2019 at 13:55
-
$\begingroup$ en.wikipedia.org/wiki/Neutral_buoyancy $\endgroup$– JMacCommented Jul 25, 2019 at 14:05
Add a comment
|
1 Answer
$\begingroup$
$\endgroup$
Whether the object floats or sinks depends on the forces acting upon it, if you consider a model where the only forces acting upon the object are buoyancy and gravitational pool, the force equation will look as follows:
$$F_{resulting}=F_{buoyancy}+F_{gravity}=\rho_{water}Vg-mg=\rho_{water}Vg-\rho_{body}Vg$$
Where $F$ denotes a force, $\rho$ is density, $V$ is the objects volume, $g$ is the gravitational acceleration.
It is evident that in your case the densities of the object and water are equal, so we have $F_{resulting}=0$, which means the body will not experience acceleration and, in the case that it was left stationary once submerged, it will remain so.
Of course, you can consider different, more complex models, that better reflect the real world: you can account for the difference between the volume of the body and the volume of the liquid it displaces, calculate additional buoyancy provided by bubbles of air stuck to the object's surface, factor in the body's compression under hydrostatic pressure and so on and so forth.
