Question

A pond appears to be 3.9m deep. If the refractive index of water is 4/3,its actual depth is _______m
​

Answer 1

lose hopehjjjjjjjjhjoolkhhligi

Answer 2

Given:

A pond appears to be 3.9m deep. Refractive Index of water is 4/3.

To find:

Actual depth of water.

Calculation:

Let apparent depth be d_(app) and actual depth of the pond be d_(act).

Kindly remember the following expression relating the actual depth and the apparent depth with the defective index of the liquid:

$\boxed{ \bold{d_{(app)} = \dfrac{d_{(act)}}{ \mu} }}$

Putting the values in SI units:

$= > \sf{3.9} = \dfrac{d_{(act)}}{( \frac{4}{3}) }$

$= > \sf \: d_{act} = 3.9 \times \dfrac{4}{3}$

$= > \sf \: d_{act} = 1.3 \times 4$

$= > \sf \: d_{act} =5.2 \: m$

So, actual depth of pond is 5.2 metres.

Other things to know:

• Whenever we try to observe an object present on the pond bed from outside , the object appears raised.

• This depth is also known as the apparent depth.

• It is due to refraction of light (originating from the object) away from the normal at the air-water interface.

Hope It Helps.