What is Buoyancy force: Definition and 52 Discussions

Buoyancy (), or upthrust, is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus the pressure at the bottom of a column of fluid is greater than at the top of the column. Similarly, the pressure at the bottom of an object submerged in a fluid is greater than at the top of the object. The pressure difference results in a net upward force on the object. The magnitude of the force is proportional to the pressure difference, and (as explained by Archimedes' principle) is equivalent to the weight of the fluid that would otherwise occupy the submerged volume of the object, i.e. the displaced fluid.
For this reason, an object whose average density is greater than that of the fluid in which it is submerged tends to sink. If the object is less dense than the liquid, the force can keep the object afloat. This can occur only in a non-inertial reference frame, which either has a gravitational field or is accelerating due to a force other than gravity defining a "downward" direction.Buoyancy also applies to fluid mixtures, and is the most common driving force of convection currents. In these cases, the mathematical modelling is altered to apply to continuua, but the principles remain the same. Examples of buoyancy driven flows include the spontaneous separation of air and water or oil and water.
The center of buoyancy of an object is the center of gravity of the displaced volume of fluid.

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    What helium mass in a balloon to make it bouyant in air?

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  2. J

    Calculate the bouyancy of two spheres joined by a rope submerged in seawater

    m * g = mAl * g V * ρ * g = VAl * ρAl * g V * ρ * g = V * ρAl * g ρ = ρAl this does not work at all, because the upper ball must have a density smaller than that of seawater 1200kg/m3 or not?
  3. C

    Exploring the Relationship between Buoyancy Force and Gravitational Force

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  4. MatinSAR

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  5. M

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  6. M

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  8. K

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  10. Hamiltonian

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  11. K

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  13. L

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  14. M

    I calculating the buoyancy force

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  15. YoungPhysicist

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  16. chemisthypnos

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  17. K

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  18. P

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  19. Superman123

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  20. WherE mE weeD

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  21. Z

    Yes, that makes sense. Thank you for pointing that out.

    Homework Statement - [/B] What is the buoyant force that acts on a fully submerged 1-L bottle of water? What is the buoyant force that acts on it if it is full of air, not water, but is still fully submerged? Assume you'd have to hold it under water.Homework Equations - [/B]Fb= V x D x GThe...
  22. T

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  23. C

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  30. B

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  31. S

    Why is Buoyancy Force = to the density of the liquid * Vobj(submerg)*g

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  32. U

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  33. R

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  34. P

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  35. K

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  36. S

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  37. D

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  38. C

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  39. M

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  40. F

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  41. J

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  42. F

    Buoyancy Force question, having hard time starting.

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  43. A

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  44. L

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  45. A

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  46. T

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  47. K

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  48. E

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  49. H

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  50. K

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