Q. At a given place where acceleration due to gravity is $g\ {ms}^{- 2},$ a sphere of lead of density $d\ \ k{gm}^{- 3}$is gently released in a column of liquid of density $\rho\ kg\ m^{- 3}.$ If $d > \rho,$ the sphere will
A) Fall vertically with an acceleration $g\ {ms}^{- 2}$
B) Fall vertically with no acceleration
C) Fall vertically with an acceleration $g\left( \frac{d - \rho}{d} \right)$
D) Fall vertically with an acceleration $g\left( \frac{\rho}{d} \right)$
Explanation
(c) Apparent weight = actual weight $–$ upthrust
$Vdg^{'} = Vdg - V\rho g$
$\Longrightarrow \ \ g^{'} = \left( \frac{d - \rho}{d} \right)g$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.