An electric pendulum

Discussion in 'Feedback and Suggestions' started by Esmat, May 20, 2013.

  1. Esmat

    Thread Starter New Member

    May 20, 2013
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    First of all I am not sure if I am in the right place to post a comment on the ebook of Lessons In Electric Circuits. If I am not I would appreciate very much if I could be guided to place this comment. If I am, here is my comment. It is about Volume II Chapter 6 "Resonance" Section 1" An Electric Pendulum". Almost at the end of the section, the author displays a graph of the KE and PE of a mechanical pendulum. The graph tries to show that as PE increases KE decreases and vice versa. So far so good. My comment is that the graph show a dotted line in the middle of the y-axis which gives the impression that energy can be negative. Further the 2 curves appear to be of two sinusoidal separated by 90 degrees which is not the case. One of them is the square of cosine function and the other is the square of a sine function. Thanks
     
  2. Georacer

    Moderator

    Nov 25, 2009
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    I believe you are right. The graph should either be annotated with Speed and Height or be replaced.

    Thank you for your feedback.
     
  3. Esmat

    Thread Starter New Member

    May 20, 2013
    4
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    Thank you Georacer for your comment. My feeling about correcting the graph mentioned above is to move the dotted line down to the bottom of the two curves (touch the valley levels) and replace the sine (cosine) plots with (sin square) and (cosine square). I have tried several times to send an attachment with the modified graph yesterday but the system did not allow me.
     
  4. Georacer

    Moderator

    Nov 25, 2009
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    Do you need some help on attaching the file?

    Are you trying to attach it in a post in this thread? What kind of file are you trying to attach? There might be a small chance that you are not able to attach files due to you not having more than 10 posts.
     
  5. Esmat

    Thread Starter New Member

    May 20, 2013
    4
    1
    Yesterday and now I have tried to attach a matlab figure and a word file, but no luck on both.
     
  6. Georacer

    Moderator

    Nov 25, 2009
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    It's expected. Can you try to save the Matlab figure as a .png file?
     
  7. Esmat

    Thread Starter New Member

    May 20, 2013
    4
    1
    I was able to upload the graph as an .png.
     
    Georacer likes this.
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