Can someone please help me with the attached question?

Question

anonymous · Answer

attachment

experimentx · Answer

looks like upthrust related problem.

anonymous · Answer

It's related to the chapter of Total Internal Reflection.

experimentx · Answer

OH .... didn't realize that ... I thought that structure was hanging and making switch of that light.

experimentx · Answer

It's easy if you say it's total internal reflection.

anonymous · Answer

Is it? :O I found it difficult.

experimentx · Answer

when does total internal reflection occur??
just try to think it, you will get answer.

anonymous · Answer

When the angle of incidence is greater than critical angle. But how to apply the concept here?

experimentx · Answer

well, that it is ... other condition is
light must be travelling from denser to rarer medium.

anonymous · Answer

Right. But how does it relate to the water level being above F or below F? I don't get this part.

anonymous · Answer

do u hve a clear diagram, other than .docx coz i dont hve mcrsft wrd installed :P HOW COOL:D

experimentx · Answer

|dw:1335004004889:dw|

so there is no total internal reflection