Electromagnetic waves and helicopters

[ShayanJ]

Hi
I have two questions
1-How electromagnetic waves transfer information?
2-Could you give me the physical and mathematical contexts that are needed to make a helicopter or an airplane?
thanks a lot

 

[Thaakisfox]

1- the main thing is that you have a carrier wave, which is just for e.g. a sine wave. Then with a device called a modulator, you manipulate the carrier wave, with this you will get small wavelets on the carrier wave. The two parameters you can manipulate are the amplitude (AM) or frequency (FM)(i am talking about the radio now). You can transmit this using an antenna. The reciever has a demodulator in it, which rips the information, the wavelets, off the carrier wave, and you are done...

2-Its very hard to design a flyable, airplane or helicopter. You have to make extensive calculations using the not so simple equations of aerodynamics. I suggest you read some aerodynamics textbook...

 

[jtbell]

In the future, if you want to ask two completely unrelated questions, please feel free to start two separate threads about them.

 

[ShayanJ]

Hey I searched the internet a lot for a good ebook but i got no result.
And forget about books because my country has really ******** book stores.
And The same goes for my country's internet so please don't introduce online sources.
thanks a lot