Question

When a block of mass $20\text{kg}$ is fully submerged in water, the spring​ balance reads $166\text{N}$. Calculate the weight of liquid displaced. Take $g=10{\text{m/s}}^2$

• A. $34\text{N}$
• B. $24\text{N}$
• C. $64\text{N}$
• D. $14\text{N}$

Answer 1

The correct option is A $34\text{N}$

Given :
$m=20\text{kg}$
Reading of spring balance $=166\text{N}$

$⟹$ weight of body $=mg$
$⟹10\times 10=100\text{N}$

$⟹$ Reading of spring balance $=$ Apparent weight of the body$=166\text{N}$ $⟹$ We know that Upthrust on body
$⟹$ Real weight $-$ Apparent weight

$⟹200\text{N}-166\text{N}=34\text{N}$

$⟹$ From Archimedes' principle, we know that upthrust is equal to weight of the liquid displaced by the body.

$\therefore$ Weight of the liquid displaced $=$
$⟹$ Upthrust $=34\text{N}$