Question

in a vessel of 21cm depth upto what height the water should be filled so that now it appears to be half filled if viewed from the top (mue water=4/3)

Answer 1

Answer:

The water should be filled to a depth of 12 cm

Step-by-step explanation:

Let the level of water from the top be d then the real depth of the water will be := (21 - d) cm

d is also the apparent depth of the water level.

Refractive index = Real depth / Apparent depth

Refractive index = 4/3

Real depth = 21 - d

Apparent depth = d

(21 - d) / d = 4/3

3(21 - d) = 4d

63 - 3d = 4d

63 = 4d + 3d

7d = 63

d = 63/7

d = 9 cm.

The water should therefore be filled to a depth of : 21 - 9 =12 cm

Answer 2

12 is your required answer