Science Buddies: "Ask an Expert"

Hi

I'm planning to build wireless telegraph. But, my teacher wants me to make an experiment with that and make graph etc. My plan is compare morse code and international code and how long it takes the sound travels in morse code and international code. Is there any idea other than this. Please help me with that. I'm so confused. I'm in 8th grade.

Hi,

I think that any type of sound will travel at the same speed if the medium were the same. That is to say if you talk or sound a horn in the same medium (say air) then the sound will travel at the same speed and this is what is commonly known as the speed of sound.

Check it out here:
http://en.wikipedia.org/wiki/Speed_of_sound

Now what you can do is to experiment to find out how the speed of sound changes with different conditions. The website above should give you some ideas.

If you want to do an experiment with wireless telegraphy then that is something else. Wireless communications (such as cellphones, or radio signals that you receive, or your cordless phone at home) are transmitted in the form of electromagnetic waves.

Check it out here:
http://en.wikipedia.org/wiki/Wireless_telegraph

Electromagnetic waves is not the same as air pressure waves used to transmit sound.
Electromagnetic wave travel at the speed of light : http://en.wikipedia.org/wiki/Electromag ... ropagation

Doing an experiment with wireless telegraphy versus sound waves is harder I think. So read the links given above and hopefully you will get a better picture on what to do.

Good luck !