# Homework Help: Waves ~ HELP one Simple problem! Thanks!

1. Jan 8, 2008

### physicsbhelp

[SOLVED] Waves ~~~~~ HELP one Simple problem! Thanks!

1. The problem statement, all variables and given/known data.

Last edited: Jan 9, 2008
2. Jan 8, 2008

### hage567

Think of the index of refraction of the two media. What are the conditions for a phase change?

3. Jan 8, 2008

### hage567

Do you have a textbook?

4. Jan 8, 2008

### Astronuc

Staff Emeritus
5. Jan 8, 2008

### hage567

Calm down. Have you tried to research it further on your own at all?

Try here instead to see if this is what you're looking for: http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/interf.html#c2

A tip: if you weren't assigned a textbook it can't hurt to look for one in the library to help you study.

6. Jan 8, 2008

### Astronuc

Staff Emeritus
OK, I think I get it. The sunlight reflected from the outer surface is reflected downward to the ground outside. If one sees a bright spot illuminated by the sun and the reflection, that would indicate contructive interference, which would imply 'in phase'.

7. Jan 8, 2008

### Astronuc

Staff Emeritus
Well, that depends on the angle. In a window, some light is transmitted, and some light is reflected.

I would suggest that tomorrow or as soon as possible, find a pane of glass and look at the reflection and transmission as a function of angle to the sun, or do so with a window.

Or use a bright flashlight.

If one wishes to be a scientist, take the initiative and do an experiment.

8. Jan 8, 2008

### Astronuc

Staff Emeritus
I guess I'm trying to have you determine the answer without giving it to you.

Is there any reason that the reflection would be inverted, i.e. the reflected E/B fields would be inverted?

9. Jan 8, 2008

### olgranpappy

10. Jan 8, 2008

### olgranpappy

11. Jan 8, 2008

### physicsbhelp

okay thank you for the help

12. Jan 9, 2008

### Shooting Star

Another first for me in the forum. Astronuc has gone crazy, talking to himself and hage567 is trying to pacify him. olgranpappy is fed up and sad and refuses to give any answer. Ultimately, physicsbhelp thanks all of them for their behaviours!

There has to be some rule where the OP can't vanish from a thread without leaving at least his original post. I recently encountered another similar one, where the thanking had been done in the first post (after editing), but there the question was at least there in some form in the replies.

13. Jan 9, 2008

### olgranpappy

that is hilarious.

[edit: LOL]