Question

. A ball weighing 4 kg of density 4000 kgm-3 is completely immersed in water of density103 kgm-3. What will be the buoyant force acting on it?
1 point

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Answer 1

Mass of ball m = 4 kg Density of ball ρ = 4000 kg/m3 Volume of the ball V = m/ρ = 4/4000 m3 = 10-3 m3. Buoyant force or upthrust acting on the ball = Volume of water displaced x density of water x acceleration due to gravity = 10-3 m3 x 1000 kg/m3 x 9.8 m/s2 = 9.8 kg.

Answer:

Buoyancy force can be calculated with the equation Fb=Vs×D×g, where Fb is the buoyancy force, Vs is the submerged volume, D is the density of the fluid the object is submerged in, and g is the force of gravity. 

In this case, the weight of the ball is 4 kg and the density of the ball is 

4000kg/m3. Therefore the volume is given as V=dm=40004m3. Substituting the given values in the equation, we get,

Fb=VsDg=40004m3×1000 kg/m3×10m/s2=10 N.