First slide

Fluid statics

Question

A ball of relative density 0.8 falls into water from a height of 2m. The depth to which the ball will sink (neglect viscus force)

Moderate

A

8m
B

2m
C

6m
D

16m

Solution

Velocity with which it hits the water surface $\sqrt{2 g . (2)} m / s$
Net force inside $mg - {vd}_{1} g$ .
$\begin{array}{l} F = mg - m \frac{d_{l}}{d_{s}} g \\ F = mg (1 - \frac{1}{0 .8}) = \frac{- mg}{4} \end{array}$
So it moves down with retardation g/4.
Stopping distance $\frac{v^{2}}{2 a}$
$= \frac{2 . g 2}{2 . g / 4} = 8 m$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App