(New page: === Energy === I will calculate the energy expended by the signal <math>sin(2t)</math> from <math> t = 0 </math> to <math> t = 8\pi </math> - <math>E = \int_{0}^{8\pi} \mid sin(2t) \mid^...)
 
(Energy)
 
Line 3: Line 3:
 
I will calculate the energy expended by the signal <math>sin(2t)</math> from <math> t = 0 </math> to <math> t = 8\pi </math> -
 
I will calculate the energy expended by the signal <math>sin(2t)</math> from <math> t = 0 </math> to <math> t = 8\pi </math> -
  
<math>E = \int_{0}^{8\pi} \mid sin(2t) \mid^2\, dx </math><br>
+
<math>E = \int_{0}^{8\pi} \mid sin(2t) \mid^2\, dx </math>
  
 
Integration shows us that:
 
Integration shows us that:
Line 10: Line 10:
  
 
<math> E = 4\pi </math>
 
<math> E = 4\pi </math>
 +
 +
==Power==
 +
 +
I will now calculate the average power of the same function from 0 to 8<math>\pi</math>.  Power is very easy to calculate once you have the Energy. 
 +
 +
<math>P = \frac{1}{8\pi-0}\int_{0}^{8\pi} \mid sin(2t) \mid^2\, dx </math>
 +
 +
Now for the easy part.  Since I already know <math>\int_{0}^{8\pi} \mid sin(2t) \mid^2\, dx = 4\pi</math> all that's left to do is divide by 8<math>\pi</math> which yields
 +
 +
<math>P = \frac{\pi}{2}

Latest revision as of 17:25, 4 September 2008

Energy

I will calculate the energy expended by the signal $ sin(2t) $ from $ t = 0 $ to $ t = 8\pi $ -

$ E = \int_{0}^{8\pi} \mid sin(2t) \mid^2\, dx $

Integration shows us that:

$ \int_{0}^{8\pi} \mid sin(2t) \mid^2\, dx = t/2-\frac{\sin(2t)\cos(2t)}4 $ evaluated from 0 to 8$ \pi $.

$ E = 4\pi $

Power

I will now calculate the average power of the same function from 0 to 8$ \pi $. Power is very easy to calculate once you have the Energy.

$ P = \frac{1}{8\pi-0}\int_{0}^{8\pi} \mid sin(2t) \mid^2\, dx $

Now for the easy part. Since I already know $ \int_{0}^{8\pi} \mid sin(2t) \mid^2\, dx = 4\pi $ all that's left to do is divide by 8$ \pi $ which yields

$ P = \frac{\pi}{2} $

Alumni Liaison

Recent Math PhD now doing a post-doctorate at UC Riverside.

Kuei-Nuan Lin