Question

A cork has weight mg and density 25% of water’s density. A string is tied around the cork and attached to the bottom of a water-filled container. The cork is totally immersed. Express the tension in the string in terms of the cork weight mg.

Answer 1

Answer:

Explanation:

Given

Density of Cork $\rho _c=0.25\rho _{water}$

Considering V be the volume of Cork

Buoyant Force will be acting Upward and Weight is acting Downward along with T

Since density of water is more than cork therefore Cork will try to escape out of water but due to tension it will not

we can write as

$\rho _{water}Vg-\rho _Cvg-T=0$

where T=tension

Thus Tension T is

$T=Vg(\rho _{water}-\rho _c)$

Taking $\rho _c$ common

$T=\rho _cVg(\frac{\rho _{water}}{\rho _c}-1)$    

$T=mg(\frac{\rho _{water}}{\rho _c}-1)$

$T=mg(4-1)$

$T=3mg$