The water -missar system behave like a planoconwex less whose curved surface is silvered , as a concave mission .
power of the peano -convex less is :
Pl=∣∣∣(μ−1)(1R1−1R2)∣∣∣ {less Makes formula}
For water, μ given , R1→∞ and R2=R
⇒Pl=(μ−1)R
also, power of missor in, Pm=−2R
so, equivalent power of rivered less would be :-
P=−(Pl+Pm)=−(M−1R−2R)=(3−M)R
Which given focas length ,f=−1p=R(μ−3)
and equivalent Radius of eurvature:R=2f=2Rμ−3
so, at height R=2Rμ−3, all rang would be normal to the silvered and where image and object wolud eoincide.
⇒ distance from water source ,d=2R(μ−3)→ case {ii}
however , as h→0, system behave a simple concave mirror , and placing an
object at c would result forming an image at c itself
⇒d=R→ case {i}