Question

A ball of relative density $0.8$ falls into water from a height of $2m$ above the surface of water. The depth inside water upto which the ball will sink is:

(neglect viscous forces)

• A. $8m$
• B. $2m$
• C. $6m$
• D. $4m$

Answer 1

Answer: (A)

$8m$

By Work - Energy Theorem,
$W=K_f-K_i$
$0.8Vg2+(0.8Vg-1Vg)d=0-0$
$1.6+(0.8-1)d=0$
$d=\frac{1.6}{0.2}=8m$