A body is suspended by a light string. The tensions in the string when the body is in air, when the body is…
A body is suspended by a light string. The tensions in the string when the body is in air, when the body is totally immersed in water and when the body is totally immersed in a liquid are respectively $40.2 \mathrm{~N}$, $28.4 \mathrm{~N}$ and $16.6 \mathrm{~N}$. The density of the liquid is
Density of water-Density of air $\propto T_{\text {water }}-T_{\text {air }}$
Density of liquid-Density of water $\propto T_{\text {liquid }}-T_{\text {water }}$ Now, from given values,
$T_{\text {water }}-T_{\text {air }}=T_{\text {liquid }}-T_{\text {water }}$
Air density $=1 \mathrm{~kg} / \mathrm{m}^3$
and water density $=1000 \mathrm{~kg} / \mathrm{m}^3$
So, liquid density $\approx 2000 \mathrm{~kg} / \mathrm{m}^3$