Critical Angles (1 Viewer)

[beau :o]

Hey all, I need someone to tell me about critical angles. From brief web surfing I know that when the angle of incidence exceeds the critical angle no light is refracted but I need a lil more insight.

Sorry if it's a dumb question, but the teacher has neglected to teach us about it and there's nothing at all in the txtbook

P.S - If anyone could give me an example of a 'Black Box' question in the electriec circuits topic it would be much appreciated. tia ^^

 

[beau :o]

Nvm about the critical angle, found a website describing it in great detail http://www.glenbrook.k12.il.us/gbssci/phys/Class/refrn/u14l3c.html

Still looking for black box question though!

 

[acmilan]

Im not sure which black box you are referring to but there are a few different types:

- planes have a black box that records voices and sounds in the plane
- a black box can also be a resistor placed in series across a telephone line to cause telephone company equipment be unable to detect calls, hence getting free calls
- in a sense a black box can be thought of as a device that operates without people understanding the internal processes, a video recorder can be considered a black box as ordinary users dont understand how it operates (when software is created it is often tested as a black box where the internal processes are ignored and only what comes in and out of the software is tested)

Im not sure if these answer what you need

 

[Xayma]

Well I highly doubt it is the plane black box acmilan, purely due to the fact that:
a) they are bright orange
b) there are two in each plane

A cockpit voice recorder and a flight instrument recorder

 

[beau :o]

I was thinking more like this, about halway down

http://www.math.bcit.ca/examples/elex/linear_algebra/backgd2.shtml

My teacher tends to be a bit of a exam nazi so if anyones got any beauties hit me up ^^

 

[acmilan]

Well in terms of that site i think a black box is purely an instrument where the internal processors are ignored and only what is input and output is studied (similar to my example of black box testing software where the internal processes are not tested, only what comes in and what goes out of the box)