Microwave/Electromagnetic Wave Science Fair

[deleted-785842]

Hey Science Expert,
Sofia and I have a question about our science fair. We are doing an experiment to find the relationship between the wavelength of an electromagnetic wave in a microwave to the wattage of the said microwave. How would you describe the relationship between power and waves? More specifically, can you see a clear relationship between wavelength and power of frequency and speed are held constant? Thank you so much,
Ana and Sofia

[LeungWilley]

Hi Ana and Sofia,
This sounds like an interesting project but I am afraid the physics doesn't sound quite right.

There are NO direct relationship between wattage (power) of a microwave oven and the wavelength of the electromagnetic (EM) wave that it generates. In the higher wattage microwave oven, you are generating more EM wave at the same wavelength (which carries more energy to the object that you are trying to heat up).

Was there a particular resource / research that led you to this hypothesis? May be I am missing something?

Good Luck!
Willey

[deleted-785842]

Hey Willey,
Thank you so much for responding, your feedback definitely saved our science fair project. We ended up changing our procedure to measure how the addition of a material in which em waves travel before reaching the food affect the speed of the waves. We did this by placing microwave safe plastic covers and various microwave safe glass Tupperware over the eggs, and measuring the distance between hotspots on the eggs. As expected, the calculated speed of the waves changed as we changed the additional medium. Strangely though, it appeared that the wavelength and thus the speed of the waves increased (for frequency remains constant). Can you speak to this in any way or explain the phenomenon that occurred? We are quite perplexed by how consistent our results were and yet how different they were from what sources are saying about how the speed of light is affected by additional media. If you possible, we can send you our data via email. Thank you so much -Ana and Sofia

[LeungWilley]

Hi Ana and Sofia,
I am glad to hear that your science experiment is going well! I am in agreement with you that the additional material should have caused a decrease in speed since the index of refraction of almost everything is going to be worse than air. This is a pretty neat java example:
https://micro.magnet.fsu.edu/primer/jav ... index.html

Is it possible to for you to post the formula that you are using to calculate the speed please? May be there's something in the equation that we need to adjust.

Thanks!
Willey

[deleted-785842]

Hey Willey,
To calculate speed, we are using v=wavelength times frequency. Frequency of the microwave can be found on the microwave output label, and the wavelength is found by measuring the distance between hotspots on the egg being cooked (Times 2). I don’t think there is any particular way to adjust that formula but we would love your input here.
Thanks so much, Ana and Sofia

[LeungWilley]

Hi Ana and Sofia,
I am afraid I am stumped. The formula that you are using is fine.

The only explanation that I could come up with that would potentially explain this is that you have somehow created a vacuum when you start adding the microwave safe covers, etc... If that's the case, the velocity of the wave could be slightly faster. (It would be really interesting to see if this can be duplicated with a vacuum sealed container or something similar)

Also, one other thing to double check is the level of uncertainty (estimated error) of your measurements. We would just want to make sure that the "estimated error" isn't so high that would invalidate the differences in results.

Willey

[deleted-785842]

Willey,
First off, we just wanted to thank you so much for responding so quickly to all of or questions and greatly helping us with our science fair. These past few days, I've done more research on a project than I have in my entire life and I've come to the conclusion that it was not the wave speed changing, but rather the frequency and wavelength due to loss of energy. The speed of em waves is fixed, before and after entering and exiting a transparent medium, respectively. By looking at the formula showing the energy of a photon, E= h times frequency, you can see that there is a direct correlation between frequency and energy, and therefore an indirect relationship between wavelength and energy. I believe that this is what is occurring in or experiment due to both the specific heat capacities of the cover materials and the raman effect. Can you confirm the previous in any way, or if there is anything you find to be incorrect, please let us know. Thanks again
-Ana and Sofia

[LeungWilley]

Hi Ana and Sofia,
That's a great explanation / research you have done!

Unfortunately, I don't have any way to confirm this but your hypothesis / background research sounds very reasonable. (May be time for a follow-up experiment? )

Again, excellent research!
Good Luck with your science fair!
Willey