A body floats in a liquid contained in a beaker. The whole system as shown in figure falls freely under gravity. The upthrust on the body is -

Question

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Solution:

When the system falls freely under gravity, it experiences weightlessness. In a state of weightlessness, the effective gravity ( $g^{'}$ ) becomes zero.

The upthrust (buoyant force) on a body immersed in a fluid is given by Archimedes' principle:

$F_{B} = ρ_{l i q u i d} V_{s u bm er g e d} g^{'}$

Since $g^{'} = 0$ during free fall, the upthrust $F_{B}$ becomes zero.

Therefore, the upthrust on the body is zero.

The final answer is $A$ .

Physics - Fluid Question with Solution | TestHub

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