Question

How much water should be filled in a container 21 cm in height, so that it appears half filled when viewed from the top of the container (given that ${}^a{\mu }_w=\frac{4}{3}$

• A. 8.0 cm
• B. 10.5 cm
• C. 12.0 cm
• D. None of the above

Answer 1

The correct option is C

12.0 cm

To see the container half - filled from top, water should be filled up to height x so that bottom of the container should appear to be raised upto height (21 - x).

As shown in figure apparent depth $h^{\prime }=(21-x)$

Real depth h = x

$\therefore \mu =\frac{h}{h^{\prime }}\Rightarrow \frac{4}{3}=\frac{x}{21-x}\Rightarrow x=12cm$