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Me!im in distress!

  1. Oct 12, 2005 #1
    plzz help me!im in distress!

    hello there .attached is a sheet of my mechanics exam review problems..
    plz check as to whether my approach is right or wrong!!

    for question 1)in the first part where they want to know the value of the angle where the masses move at constant speed..i equated the motions of equations of the 2 masses and then put the acceleration to zero.by this way i reduced the equations to:

    sin(theta)-(nu)cos(theta)=1/2

    where (nu) is the coeff of kinetic friction given..
    and then i evaluated theta in terms of sine inverse...the value was in terms of nu though and it was a huge term(i substituted sin (theta) for x and accordingly solved the equation for x!!
    Now since this part says that there could be more than one angle where the masses move with constant speed...i am wondering as to whether i am supposed to reverse the direction of motion of the masses that i had taken initially so as to get 2 new equations and another value of theta for which the masses move at constant speed...????
    would u plz check if this is right...


    also i wanted sumone to gimme a heads up on the other questions

    especially questions 2 and 3..I mean for question 2 (a) in which the force is supposed to be minimum..do i have to calculate theta when i equate (nu) to be zero...as the the force of friction will be negligible then,,,and in 2(b)??
    please help...iv gotta finish this review asap..and am stuck!please guide me with these 5 questions..atleast gimme an idea if u think im goin wrong!!

    THE REVIEW PAPER IS ATTACHED HEREWITH!! IS KINDA TINY SO PLZ BEAR WITH ME!(THE ALLOWED SIZE WAS 100 KB THEREFORE!!!)
     

    Attached Files:

  2. jcsd
  3. Oct 17, 2005 #2

    Tom Mattson

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    Gold Member

    Sorry for the late reply. I am going to hazard a guess as to why your thread did not receive any responses: Your work is difficult to follow.

    If you are still interested in feedback on this then I'd like to ask you to clearly present the steps you took. It will make it easy for people to spot errors in your reasoning. As it stands now, no one can help you with this without actually doing the problem in full.
     
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