Monday, February 18, 2013

Work Cited

        
Work Cited
Anitei, Stefan. "How Does the Radio Work?" - Softpedia. Softpedia, 2001-2013. Web. 18 Feb. 2013.      
       <http://news.softpedia.com/news/How-Does-the-Radio-Work-75702.shtml>.

Borade, Gaynor. "How Does the Radio Work." Buzzle.com. Buzzle.com, 08 Oct. 2011. Web. 18 Feb.     
      2013. <http://www.buzzle.com/articles/how-does-a-radio-work.html>.

Brain, Marshall. "How Radio Works." HowStuffWorks. N.p., n.d. Web. 18 Feb. 2013.
      <http://electronics.howstuffworks.com/radio.htm>.

Smith, Steve. "How Do Radio Stations Work?" EHow. Demand Media, 08 Apr. 2009. Web. 18 Feb.
      2013. <http://www.ehow.com/how-does_4899946_radio-stations-work.html>.

Cosine Graphs

How to Graph a Cosine Graph

A Cosine graph has a parent equation of y=a cos bx.

"a" dictates the amplitude. The distance between a peak (or trough) and the mid-line. Also known as half the distance between "peak" and "trough" on the graph. A negative a reflects the graph "upside down".

"b" is the number you will use to find the period and frequency of your graph. To find period set up the equation p=2π/b with "p" being your period. When making the graph the Period is how long it takes the function to complete 1 full cycle. So from the maximum to the center to the minimum, then back up to the center then the maximum.

Once you find the period you need to find the intervals to put your "key points" on your graph. Take the number you found for your period and divide it by 4. That is how much you will go over by until you get to the period number.

Key points are the points that show the minimum, maximum, and center points of your graph. when making a cosine graph your first point is at (0,amplitude) then you go to center line, down to the minimum, then back to the center line, and then back to the maximum. At this point you should be to the period number of your graph and have 1 complete cycle elapsed.   


Below is an example of a cosine graph with an amplitude of 1 and a period of 2π. This is the parent graph of a cosine function.









Thursday, February 14, 2013

Fox-Hole Radio

How a Radio Works

A radio will receive electromagnetic waves sent out by a transmitter. These waves are transmitted into sound waves through a radio. The waves sent through the air are different sound waves. These sound waves follow the sine/cosine wave pattern. Each different radio uses a different sine wave at a different frequency. That is how they are separated. Different amplitudes and frequencies create different sounds., such as tuning forks work. The larger the tuning fork, the greater the amplitude (louder the sound), and the smaller frequency (lower pitch). Radio's work in the same way by sending out different sized waves into the air to be received and interpreted by the receiving radio. An AM radio recognizes a difference  in the amplitude of the waves. AM radio's typically will not play very much music and well be more talk and information. An FM radio recognizes the varying frequency of the waves. This allows music to be transmitted through space and recieved, then turned into what we hear.
Parts of the radio
The Mechanism- Is the part of the radio that creates the energy and allows the radio to turn waves into sound.
The Transmitter- Produces the Alternating current and makes the energy to produce a signal
Transmitting Antenna- Takes the signal and sends it out into space
Receiving Antenna- intercepts the electromagnetic waves

Radio stations use a radio tower to send signals out to everyone within reach. In some cases, these signals are sent for miles, and each one has a different frequency.The frequency is recieved by a reciever or a stereo in this case. Each station has a set frequency to the dial. So, when u set your dial to 106.7, you are setting your stereo to only listen to that type of frequency sound waves.

How to build a Fox-Hole Radio
First we wrapped a 5 inch PVC pipe with copper wire 120 times, making sure there is a good amount left on one end. Then we placed paper clips so we had one to hook up a ground wire, speakers, and antenna. Then we drilled the PVC pipe to the block of wood. We drilled in a razor blade that was fired. We connected a pencil to a safety pin so that the lead of the pencil was touching the safety pin. We placed the lead of the pencil on the razor blade on the part that was fired. We used copper wire to connect the ground wire, to the speakers, then to the paper clip that touches the copper wire on the PVC pipe. We took more copper wire and connected the other head speaker paperclip to the safety pin with the pencil on the  end. Use the extra wire from the PVC pipe and connect it to the antenna paper clip then to the razor blade. Make sure you sand all the connections to get the coating off it will produce better sound.


http://news.softpedia.com/news/How-Does-the-Radio-Work-75702.shtml
http://electronics.howstuffworks.com/radio.htm
http://www.buzzle.com/articles/how-does-a-radio-work.html
http://www.ehow.com/how-does_4899946_radio-stations-work.html

Monday, February 11, 2013

Sine Graphs

How to Graph a Sine Graph

A Sine graph has the parent equation of y=a sin bx.
"a" dictates the amplitude. The distance between a peak (or trough) and the mid-line. Also known as half the distance between "peak" and "trough" on the graph. A negative a reflects the graph "upside down".

"b" is the number you will use to find the period and frequency of your graph. To find period set up the equation p=2π/b with "p" being your period. When making the graph the Period is how long it takes the function to complete 1 full cycle. So from up to down and back up again.

Once you find the period you need to find the intervals to put your "key points" on your graph. Take the number you found for your period and divide it by 4. That is how much you will go over by until you get to the period number.

Key points are the points that show the minimum, maximum, and center points of your graph. when making a sine graph your first point is at (0,0) then you go up once, down to the center, then all the way down to the minimum, and then back to the center line. At this point you should be to the period number of your graph and have 1 complete cycle elapsed.   

Below is an example of a sine graph with an amplitude of 1 and a period of 2π. This is the parent graph of a sine function.