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Homework Help: Angular Motion on a Plane

  1. Nov 15, 2005 #1
    The human body can safely stand an acceleration 9 times that due to gravity. With what minimum radius of curvature may a pilot sfely turn the plane upward at the end of a dive if the plane's speed is 770km/h.


    i did a quesotin before this, which had a roller coaster
    i did mgh at a = 1/2 mv square at a + mgh b. my v square was derived
    froma free body diagram i drew, and i set mvsquare/r = fnet
    and rearranged until i had the equation equal to V.
    and then solved for H (from mgh at a) and i got the answer.
    For this i dont know wat to do, can i use the same formula, but i dont have both heights, just the first one
    i just wanted a startup
     
  2. jcsd
  3. Nov 15, 2005 #2

    Fermat

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    The problem has to do with centripetal acceleration.

    Can you see how to set up eqns for centripetal acceln/force from the info given ?
     
  4. Nov 15, 2005 #3
    energy isnt necessary for this question. It's all centripetal motion.
     
  5. Nov 15, 2005 #4
    reallyy! so this is different from the roller coaster q
    im surprised now
    what formulas may help
     
  6. Nov 15, 2005 #5
    somebody........
     
  7. Nov 15, 2005 #6

    Fermat

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    What is the formula for the centripetal force on a body travelling in a circle,of radius R, with an angular velocity of ω ?
     
  8. Nov 15, 2005 #7
    v = w square tiems r?

    or
    mv square over r
     
    Last edited: Nov 15, 2005
  9. Nov 15, 2005 #8

    Fermat

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    Ok, this becomes,

    Fc = mv²/r

    and you want to find r.

    What is the maximum value that Fc can be such that the pilot only experiences 9g ?

    Then solve for r.
     
  10. Nov 15, 2005 #9
    kkk i see
    what bout mass
    can i lave that 1?
     
  11. Nov 15, 2005 #10

    Fermat

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    The mass will cancel out.
     
  12. Jul 3, 2006 #11
    ans.....518.69 meters
    how disgracful of u guys. cant even solve such easy question.
    haha....got outbeaten by a 14 year old nutcase
     
  13. Jul 3, 2006 #12

    Hootenanny

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    It is much more productive, if one guides a poster through the question rather than providing answers or solutions. What has SS2006 gained from your post?
     
  14. Jul 3, 2006 #13
    One would hope only confirmation, because if he's still waiting on an answer then his assignment might be a bit late. ;)
     
  15. Jul 3, 2006 #14

    Hootenanny

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    Didn't spot the date:wink:
     
  16. Jul 3, 2006 #15
    lol...sry guys..i jus did dat for fun...
    ok here it goes....
    mv(squared)/radius=m9g
    if you sub. in the values of the porblem by making r the subject of the formula, i got the ans.
    radius=v(sqaured)/9g
    were v is velcity, m is mass and g is 9.8ms(sqaured).
    remeber to convert the km/h into m/sec.
    sry for any hurt feelings
    that wus jus for fun,
    regards
    vijay
     
  17. Jul 3, 2006 #16
    lol, i glanced through the pages and found this, the prob. wus easy yet know one gave a definate ans to the solution. thats were i budged in......sry..guys.
     
  18. Nov 22, 2011 #17
    how we should cancel m by this formule mv^2/r = ma ?
     
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