Hydrostatics - Buoyancy | MCAT Physics Prep

[@user-cu8vc3qn4z]

I just want to say thank you! I was really struggling to understand the concept behind the equations in the physics section and now I feel like everything makes much more sense after you've explained the purpose of each variable and equation!

[@angelaschroeder1256]

This is the most helpful video I have watched on this topic! thank you for such a straightforward, simple, and effective video!

[@MedSchoolCoachMCATPrep]

You're so welcome!

[@fabiferreira865]

Most helpful video I have watched on fluids so far definitely will be watching more videos, thank you so much!!

[@MargaretSmith-d2o]

Why is the atmospheric pressure the same at different depths (you mention that the atmospheric pressure is the same everywhere In the beginning of the video) considering that atmospheric pressure is less at higher elevations?

[@tommyguir3820]

amazing video!!!! thank you!

[@lakerssuperfan149]

Thank you so much for your detailed explanation i found it realy helpful!

[@MedSchoolCoachMCATPrep]

Glad it was helpful!

[@dallascowboy2221]

I actually enjoyed that and solved his super easy example by guessing the obvious lol.

[@matthewmorris130]

Awesome, thank you so much!

[@actorQ]

Great video.

[@tomtroszak]

Ken, the buoyant force is not due to a pressure difference above and below a submerged object. Consider three identically dimensioned submerged objects, each with an identical pressure difference above and below. But as they are made of steel, wood, and styrofoam respectively, they will exhibit very different bouyant forces.

[@MedSchoolCoachMCATPrep]

The buoyant force is equal to the density of the fluid x volume of the fluid displaced x gravity. It does not depend on the material/density of the object. The difference between those objects is the gravitational force they experience. Assuming all three are submerged, they all experience the same buoyant force.

[@tomtroszak]

@@MedSchoolCoachMCATPrep Thanks for the comment! You are right, I didn't state my argument succinctly. I need to find a better way to say it. You wrote "The buoyant force (...) does not depend on the material/density of the object...The difference between those objects is the gravitational force they experience. Assuming all three are submerged, they all experience the same buoyant force." Ok...last time I checked, "gravity" was not a force, but an acceleration that applies equally per unit of mass to both the fluid and the object. Therefore the *weight* of fluid displaced by an object cannot normally be greater than the *weight* of the object. Therefore, the "bouyant force" is very different for all three objects, which normally would not be submerged equally. In fact if the fluid is water, the bouyant force for the steel object would be negative, the styrofoam would be positive, and the wood could go either way depending on its density. Lemme think about it for a minute, and I'll get back to you.