Very basic trigonometry question

Discussion in 'Physics & Math' started by Lilalena, Jul 19, 2013.

  1. Motor Daddy Valued Senior Member

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    I can, but as I said before, NO FREE LESSONS FOR YOU! You want to pay?
     
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  3. Tach Banned Banned

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    No, you can't. See here
     
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  5. Motor Daddy Valued Senior Member

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    I could use the extra money...

    ...but, I'm easy, but not cheap!
     
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  7. Tach Banned Banned

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    You can't. See here.
     
  8. Motor Daddy Valued Senior Member

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    This is my last response to you about this matter until you back up your wild and crazy assertions. Put up or shut up!
     
  9. Tach Banned Banned

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    Don't get all twisted in your knickers, we all know you can't.
     
  10. Brian72103 Registered Member

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    This is entertaining - it is like watching Sheldon and Leonard have an argument.
     
  11. rpenner Fully Wired Valued Senior Member

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    Post #3 of this thread
    has an image that appears to be identical to the [POST=3062623]post #159 on April 20 of this year[/POST] which appears to be a screen capture of [POST=2917299]post #25 on March 20-21 of last year[/POST], where Motor Daddy was learning the description of one-dimensional motion with constant acceleration. He would also post a screen capture in [POST=2917781]post #34[/POST] of that earliest thread entitled "Acceleration and Deceleration from known height".

    Please favor AlphaNumeric and James R's posts over those of Motor Daddy (too ignorant) and Tach (too shrill).
     
  12. Motor Daddy Valued Senior Member

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    Thanks for finding the link.

    So like I said, Tach was talking crap, as usual!
     
  13. Lilalena Registered Senior Member

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    Tach,
    I think your posts make the most sense but also I found a chart in an old physics textbook
    and it seems to explain d=16t^2 completely.

    So the 16 is neither 'g' nor a constant 'a' but the distance the object covered in the first time interval (if one decides to make a chart).

    Time Interval :::::::: Ave V :::::: Distance Traveled :::::::::: Cumulative Distance :::::::::

    0-1 :::::::::::::::::::: 5 m/s :::::::::::::::::::::: 5 m ::::::::::::::::::::: 5 m
    1-2 :::::::::::::::::::: 15 m/s :::::::::::::::::::: 15 m :::::::::::::::::::: 20m
    2-3 :::::::::::::::::::: 25 m/s :::::::::::::::::::: 25 m :::::::::::::::::::: 45m
    3-4 :::::::::::::::::::: 35 m/s :::::::::::::::::::: 35 m :::::::::::::::::::: 80m


    You can arrive at d=80m by

    d = 5t^2 where 5 is the distance covered in the first interval
    d = 5(4)^2 = 80m


    Another try, for cumulative d=45m

    d = 5t^2
    d = 5(3)^2 = 45m



    My question now is, which of the kinematic equations covers this relationship and also what do you call a proportional relationship such as this where the numbers work but the units don't? Because the resulting units here would be m-s^2
     
    Last edited: Jul 29, 2013
  14. Lilalena Registered Senior Member

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    Sorry I could not come back to this earlier as work got a bit intense
     
  15. Motor Daddy Valued Senior Member

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    where:
    \(d\) is the distance
    \(u\) is the initial velocity
    \(v\) is the final velocity
    \(a\) is the acceleration
    \(t\) is the time of travel

    \(d=ut+\frac{1}{2}at^2\)

    The units m/s^2 are units of ACCELERATION. Acceleration is the rate of change of velocity.

    Your d=5t^2 is saying that the distance the object travels is equal to 5 times the time squared. If the time is one second then the equation is d=5(1^2), or d=5. So the distance the object traveled in one second is 5 meters.

    It started with an initial velocity of 0 m/s, and one second later it had traveled 5 meters. That is an acceleration of 10m/s^2. \(a=\frac{2(d-ut)}{t^2}\)

    For every second the object travels, the object's velocity increases 10 m/s. So at t=1 the object has a velocity of 10 m/s. At t=2 the object has a velocity of 20 m/s, at t=3 the object has a velocity of 30 m/s.

    So the DISTANCE that the object traveled is \(d=ut+\frac{1}{2}at^2\), where \(u\) is the initial velocity (0 m/s), \(t\) is the time of travel, and \(a\) is the acceleration (10 m/s^2).
     
    Last edited: Jul 29, 2013
  16. Tach Banned Banned

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    [/QUOTE]

    \(d=\frac{g}{2}t^2\)

    If \(g\) is expressed in \(\frac{ft}{s^2}\) then \(g=32\) and \(\frac{g}{2}=16\).

    If \(g\) is expressed in \(\frac{m}{s^2}\) then \(g=9.8\) and \(\frac{g}{2}=4.9\).
     
  17. Motor Daddy Valued Senior Member

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    There is a beach ball at rest on the beach. You claim g=9.8 m/s^2 at sea level. I start my stopwatch. I stop the stop watch 10 seconds later at t=10.

    Are you trying to tell me the distance the ball traveled is \(d=\frac{g}{2}t^2\)? So you're saying the ball traveled 490 meters in that 10 seconds? Is that what you're saying, Tach??
     
  18. Tach Banned Banned

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    What gives you this bright idea?
     
  19. Motor Daddy Valued Senior Member

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    I asked you a question. I'll break it down for you into simpler terms, since you have comprehension problems.

    Do you claim g=~9.8 m/s^2 at sea level?
     
  20. Tach Banned Banned

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    You don't know even this? Go back, take remedial physics.
     
  21. Motor Daddy Valued Senior Member

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    Again no answer to my question. You leave me no choice but to conclude that you're scared to answer my direct questions, because you know they make you look ridiculous, as is your equation.

    Answer my direct question: Approximately what is g equal to at sea level, 9.8 m/s^2?
     
  22. Tach Banned Banned

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    Nope, the distance traveled in the FIRST second is 5m. The distance traveled in one second is a DIFFERENT number.
     
  23. Tach Banned Banned

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    Learn proper English, the above is gibberish. Also, learn manners.
     

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