A coin lies on the bottom of a lake `2m` deep at a horizontal distance `x` from the spotlight (a source of thin parallel been of light) situated `1m` above the surface of a liquid of refractive index `mu = sqrt(2)`) and height `2m`. Find `x`.

Explanation

`sqrt(2) = (sin 45^(@))/(sin r)`
`rArr sin r = (1)/(2) rArr r = 30^(@)`
`x = RQ + QP`
`1m + 2tan 30^(@)m`
`= (1 + (2)/(sqrt(3)))m`