Buoyant force

🌈  Mind map Buoyant force 

●  When a body is partially or completely immersed in a liquid, it experiences an upward force due to the liquid which is called the Buoyant force. 

● The pressure at the bottom of an object submerged in the fluid is greater than that at the top. The difference in this pressure results in a net upward force Buoyant force) on the object.

● The buoyant force is equal to the weight of the liquid displaced by the body.

● The buoyant force depends on : 

(i) the volume of the body immersed in the liquid (larger the volume of body immersed in a liquid, greater is the buoyant force). 

(ii) the density of the liquid in which the body immersed (more the density of liquid, greater is the buoyant force).

iii) Acceleration due to gravity. 

● Case 1: The weight of the body W is greater than the buoyant force FB. In this case, the resultant force on the body is (W - FB) which acts downwards. The body will sink in the liquid. 

● Case 2: The weight of the body W is equal 

to the buoyant force FB. In this case, the resultant force on the body is zero,so apparent weight is zero.

 

 ● Case 3: The weight of the body W is less than the buoyant force, if the body is completely immersed in liquid. In this case, the resultant force acts on the body upwards. The body will float partially above the surface of liquid. Only that much portion of the body will immerse inside the liquid by which the weight of the liquid displaced FB balances the total B weight of the body. Now while floating FB = Weight of a body, so apparent weight is zero.

 Link for Experiment on Buoyancy 

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ARCHIMEDES ' PRINCIPLE 

When a body is immersed fully or partially in a fluid, it experiences an upward force that is equal to the weight of the fluid displaced by it.

Here's a video representation: