The size of buoyancy can be calculated by the formula: F float = ρ gV to discharge liquid (gas). Conditions for the ups and downs of an object: (an object immersed in a liquid)
(1) If F floats >: G, that is, ρ < ρ liquid, the object floats;
(2) If F floats ρ liquid, the object sinks;
(3) If F float =G object, that is, ρ object = ρ liquid, the object is suspended;
(4) If F float =G object, that is ρ object.
(5) if ρ object >; ρ liquid, the object sinks to the bottom, at this time: G object =F floating +F cup bottom supporting force (three forces balance).
Extended data:
In 245 BC, Archimedes discovered the principle of buoyancy. The definition of buoyancy is F float =G row (that is, the buoyancy of an object is equal to the gravity of the liquid displaced when the object sinks), which can be used to derive the formula F float = ρ gV row liquid (ρ liquid: liquid density, unit kg/m3; G: the ratio of gravity to mass g=9.8N/kg. Roughly, g can be taken as10n/kg; Row V: Volume of discharged liquid, in cubic meters.
Buoyancy: An object submerged in a liquid (or gas) is pushed upward by the liquid (or gas). Buoyancy direction: opposite to gravity direction, vertical upward. The reason of buoyancy is that the object immersed in liquid or gas is subjected to the upward and downward pressure difference of liquid or gas on the object.
When the top interface of the floating body does not touch the liquid, only the upward pressure acting on the bottom interface will produce buoyancy. As for the object at the bottom of the container, this phenomenon is relatively rare, because as long as there is a thin liquid film between the two, the pressure can be transmitted, there is upward pressure at the bottom, and there is a pressure difference between the upper and lower surfaces of the object, and the object will be floated.
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