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Homework Help: Coriolis forces, rotating coordinate systems

  1. Nov 6, 2006 #1
    I know that some people worship Symon's Mechanics 3rd Ed., but I find this book incredibly confusing...especially chapter 7, dealing with rotating coordinate systems. I follow the math, and perhaps the logic, but I can't even find a way to start the homework problems. The guy doesn't give any examples, and how the hell is one supposed to learn how to solve a problem when provided with nothing but dense proofs using strange notation?

    For example, problem 7.7 tells us that a body is dropped from height h above the earth. We are to calculate the coriolis force as a function of time, given that it has a negligible effect on the motion, and using the velocity of a freely falling body with acceleration Ge. Neglect air resistance, assume h is small so that Ge can be taken as constant. Then, calculate the net displacement ofthe point of impact due to the coriolis force calculated previously.

    OK , so Symon proves that Ge(r)=g(r)-w x (w x r). (The w represents omega, the Ge represents vector g subscript e.) I guess the coriolis force is the -2mw x d*r/dt term. How are we supposed to solve this. Are we just supposed to KNOW what w is? Nowhere in this chapter is w given for earth. I would think that maybe it would be (2pi/24hrs)*theta^ (if theta^=theta hat=unit vector in theta direction). Unfortunately, like Symon my professor rarely works examples either. I have no clue how to go about solving this or most other problems in the book. I there a web site out there that, say, gives clear, step-by-step examples for solving these type of problems? Or does anyone write a "companion book" to be read side-by-side with Symon's that actually works examples for problems like his?

    Why the heck did I major in Physics???
  2. jcsd
  3. Nov 6, 2006 #2


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    The only person I ever heard mention Symon on this forum is me! But I do it for 5 I think cuz it's the only mechanics book I've read. :P

    I wrote a light "summary" of the chapter on rotating coordinate systems a while back that at least answers your uncertainty regarding that the coriolis force is. Here's the thread.


    You should read the chapter until you understand every single little detail about it as if you'd yourself written it. Then no problem should pose conceptual difficulties. (In theory :biggrin:)
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