Frequency

[Goosemaster]

I was recently thinking about this and since goo ggle is down, I thought this crowd could easily field this one since I honestly donm't remember from class a year ago


Frequency is how many times a wave reiterates itself (from peak-to peak) per second (probably not a very Einsteinesque definition is it

?)


Lower frequencies have less energy.


So why exactly can those frequecies penetrate better?


Goosemaster's late-night hypothesies:


Since there is less energy, there is a lesser quantity to transfer through a substance.


Therefore a higher frequecy such as gamma rays will be obstructed moreso than lets say a radio-wave because it will have to transfer a great amount of energy through material.


anyone care to entertain me with their intelligence?



For the record, I am not stupid: Kust REALLY slocaked off last year



Now on the road to sucess, one question at a time.

 

[mandatory]

A frequency doesn't have any energy at all. It's an expression of how often something happens; f = x/unit time.

As far as penetration is concerned, penetration of what, through what?

 

[crabbyman]

I slack a lot..and I too forget the exact answer...

Its something like that....for example...AM and FM radio..sinc AM is shorter wavelength *hz* it is less like to be cut out since its a bigger sine wave...now FM..as soon as you get next to a tall building your FM is nonexistent....it has higher hz and then no waves can get to your antenna since more than one of the sine waves is cut...

 

[Goosemaster]

Originally posted by: crabbyman
I slack a lot..and I too forget the exact answer...

Its something like that....for example...AM and FM radio..sinc AM is shorter wavelength *hz* it is less like to be cut out since its a bigger sine wave...now FM..as soon as you get next to a tall building your FM is nonexistent....it has higher hz and then no waves can get to your antenna since more than one of the sine waves is cut...

mandatory,

I am refering to a wave...say a radio or gamma and its characteristics....


So basically it can be related to e=mc^2?


Energy has mass so then it has a harder time penetrateting any object because it has a higher mass?


Interesting....

 

[Shalmanese]

The reason AM penetrates better than FM is due to diffraction. FM diffracts less so tall buildings cast a "shadow". AM diffracts far more so that shadow is far less. Neither actually PENETRATE anything (in the way your referring to).

Different frequencies are absorbed better by certain things. EG. glass is completely opaque to UV light but is transperant to visible light. Some materials are opaque to visible light but transmit UV light.

 

[capybara]

each object has a resonant freq, that at which it maximally absorbs (is resistant to) incoming
frequencies. water resonates at 2.5 ghz, 25 ghz, and another higher freq i forget ( maybe
60 ghz) which is why microwaves use 2.5 ghz, the easiest of these 3 freqs
to generate high power at.
>>>>> btw, glass is not opaque at infrared, if it was, a window would be a perrfect
insulator to outside cold or hot weather. but it is resistive to infrared.

 

[imgod2u]

Not neccessarily. In the specific example of gamma rays vs radio waves is actually the wave itself. A shorter frequency would mean the wave more easily interferes (diffracts) from the material. Just visualize a wave and a piece of matter. If the wave has shorter wavelengths then it is less likely that it will pass over the object.

 

[rimshaker]

Don't confuse "penetrate better" with "traveling farther." Remember that EM waves radiate and travel in all directions. You have to consider wavelength in all this. What seems to 'penetrate better' is basically a low freq EM wave. Submarines use ultra low frequencies for example. Doesn't literally mean it's penetrating though the water, it just travels farther. This topic of power and AM/FM radio is a little different topic since it pretty much only applies to relatively short distances.

 

[capybara]

Originally posted by: imgod2u<br If the wave has shorter wavelengths then it is less likely that it will pass over the object.

but this is not a li near relationship.
object: water
test freqs: 2.5 ghz, 10 ghz
which is absorbed the most? 2.5 ghz, the longer wavelength of the two test freqs.
why: resonant freq
===============================================================
test #2
object: water
test freqs: 10 ghz, 24 ghz
which is absorbed the most? 24 ghz, the shorter wavelength of the two test freqs
why: resonant freq