1. Standard memberBowmann
    Non-Subscriber
    RHP IQ
    Joined
    17 Mar '05
    Moves
    1345
    10 Oct '05 16:36
    I've been 10½ stone for the last twenty years.

    😏
  2. Standard memberleisurelysloth
    Man of Steel
    rushing to and fro
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    10 Jan '06 18:56
    Here's an interesting "application" of this idea.

    http://www.space.com/scienceastronomy/060110_vega_cool.html
  3. Milton Keynes, UK
    Joined
    28 Jul '04
    Moves
    80198
    10 Jan '06 21:47
    Originally posted by Suzianne
    It would have to be inversely proportional to the latitude.

    As a function of the latitude, tho, I'm not at all sure about the actual angle of the tilt.

    EDIT: (And yes, I did take trig in school, but I forget most of it, hehe)
    I haven't done the calculations yet but I don't think it would be quite be inversely proportional. More like:

    F = ((v^2)/r) cos (l)

    where l is latitude.

    Will try and verify this and work out the angle of tilt relative to gravity if the earth stops moving. 🙂
  4. Milton Keynes, UK
    Joined
    28 Jul '04
    Moves
    80198
    10 Jan '06 22:11
    Ok, have confirmed that it:

    Starting from F = (v^2)/r I decided to represent the equation in terms of F, r and t to make things a little easier.

    d = 2*pi*r

    therefore F = ((2*pi*r/t)^2)/r = (4 * pi^2 * r) / (t^2)

    r would be proportional to cos(l) therefore

    F = ((4 * pi ^ 2 * r) / (t^2)) cos (l)

    Which effectively does confirm that F = ((v^2)/r) cos (l)

    Agree that it is frustrating not being able to represent equations properly on here.

    Still working on the tilt.
  5. Milton Keynes, UK
    Joined
    28 Jul '04
    Moves
    80198
    10 Jan '06 22:563 edits
    Diagram: http://www.lunacy.force9.co.uk/images/trig.jpg

    My vector addition is a little rusty but I think I got it (and referring to my very badly done drawing). After resolving:

    latitute = l = theta

    a = angle of tilt = alpha

    g = force of gravity

    z and p are just variables I used while deriving.

    h = F sin (l)

    p = F cos (l)

    z = F cos (l) + g

    tan (a) = (F sin (l)) / (F cos (l) + g)

    a = arctan ((F sin (l)) / (F cos (l) + g))

    I haven't checked this through but I believe it is correct. I am also sure it can be simplified further but haven't bothered to go that far.

    Edit: Forgot to substitute in F as in my previous post.

    F = ((4 * pi ^ 2 * r) / (t^2)) cos (l)

    a = arctan (((4 * pi ^ 2 * r) / (t^2)) cos (l) sin (l) / (((4 * pi ^ 2 * r) / (t^2)) cos^2 (l) + g))

    I will simplify it tomorrow, getting late. 😛
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