Question

A silver ingot weighing 2.1 kg is held by a string so as to be completely immersed in a liquid of relative density 0.8. The relative density of silver is 10.5. The tension in the string in kg-wt is

• A. (a) 1.6
• A. (b) 1.94
• A. (c) 3.1
• A. (d) 5.25

Answer 1

(b)

Apparent weight $= V(\rho - \sigma)g = \frac{M}{\rho}(\rho - \sigma)g\mathbf{= M}\left( \mathbf{1}\mathbf{-}\frac{\mathbf{\sigma}}{\mathbf{\rho}} \right)\mathbf{g}$

$\mathbf{= 2.1}\left( \mathbf{1}\mathbf{-}\frac{\mathbf{0.8}}{\mathbf{10.5}} \right)\mathbf{g = 1.94g}$ Newton = 1.94 Kg-wt