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Homework Help: Kind of a challenge(for me i guess)

  1. Jul 6, 2006 #1
    hello everyone , im a newbe here ,im a dentistry student ,foundation year ,to pass this year im required to pass physics ,i actualy suck at physics lol ,well i need any of you to solve this exam for me please it should be eazy for any member here i guess(i heard everyone here is really good) the catch is i need it by tomorow ,so if this is posible its much apreciated ,thanx alot :rolleyes:

    here is the link..

    Last edited by a moderator: Apr 22, 2017
  2. jcsd
  3. Jul 6, 2006 #2
    I'm only new here myself, but I'm fairly certain that's not how it works...there's certainly not many people here who will solve a whole exam for you. Are there any specific questions that you're having trouble with?
  4. Jul 6, 2006 #3


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    Indeed, the challenge is yours...

    Show some working!
  5. Jul 6, 2006 #4
    yea spesific Qs ,

    from file 2 , Q8

    from multiple choice Q6
    ^^havin problems with thos ,
    thos are the important ones , but ill be glad if u can solve the last Qin file 2

    btw , im not doin that just to get the answers , this is just a practic exam ,the real exam is similar 2 it on saturday ,so i actualy need to learn how to get the answers , anyway ill apreciate it if u can solve any of the 3 Q i mentiond up
  6. Jul 6, 2006 #5


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    Hello wicked,

    as for Question 8 in the second file:

    a) well, try to imagine which forces are acting on you right now (probably sitting in a chair), then there is another force which is responsible for the deceleration of the block in your problem.

    b) apply the energy theorem

    c) start with Newton's second law of motion; I'm not sure why the text states the coefficient of kinetic friction [tex]\mu_k=0.33[/tex] while the sketch says [tex]\mu_k=0.30[/tex]


    Last edited: Jul 6, 2006
  7. Jul 6, 2006 #6
    thats just a printing mistake , thanx alot
  8. Jul 6, 2006 #7
    but i dun get it in part A i need s to solve the prob ,and in part C they are askin me for s
  9. Jul 6, 2006 #8


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    You're welcome! :smile: Feel free to post your results. Then on to the next question! :wink:

    A small hint: the block has a certain kinetic energy at the bottom of the ramp before it enters the rough part. After the process of deceleration the block does not move, hence the kinetic energy is zero at the end. Where did it go?
    Last edited: Jul 6, 2006
  10. Jul 6, 2006 #9
    turned to potential energy?
    (remeber i suck at physics lol)
  11. Jul 6, 2006 #10


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    During the process of deceleration (from the bottom of the ramp to point D) the potential energy of the block stays the same.

    But keep the potential energy in mind for part b). :wink:
  12. Jul 6, 2006 #11
    ًًًٍُُW = PE2 - PE1 = mgh2 - mgh1

    i need h , i got m and g ofcorse , still confused bout getting W
  13. Jul 6, 2006 #12


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    The good thing about potential energy in this problem: you can choose any height as zero-level for it.

    I'd suggest setting [tex]h_1=0\,m[/tex] in your equation so that [tex]h_2=h[/tex] in the sketch.

    "Energy conservation" is the key in b)

    Right at the moment the block separates from the spring it has a certain velocity [itex]v_1[/itex] and is situated at the height [tex]h[/tex]. What does that mean for the total Energy (kinetic+potential)? At the bottom of the slope (point B) the total energy is conserved. The block "gained" kinetic energy but "lost" potential energy. It's better to speak of conversion of energy here and in general.

    Edit: The forum is quite slow for me today. Sorry if I can't give you an instant reply. :smile:
    Last edited: Jul 6, 2006
  14. Jul 6, 2006 #13
    aa for f u c k's sake can u just post the solution , i need this S#!t for 2moro i cant be discussin one Q the whole night ,gotta do 16 Q
  15. Jul 6, 2006 #14


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    :rolleyes: Challenges are meant to test us. It's up to you if you want to learn something from it or take the easy route and avoid them at all costs.

    Also: I'm sure if you'd be able to solve this specific question, the other ones will appear a whole lot easier in your eyes as they seem to deal with exactly the same basics: Newton's laws and energy conversion.
    Last edited: Jul 6, 2006
  16. Jul 6, 2006 #15
    fine fine ill do it my self , thanx anyway

    peace ,im out
  17. Jul 6, 2006 #16
    eazy route , coz this whole physics corse wont do me any good for the rest of my life,i wana be a goddam dentist
  18. Jul 6, 2006 #17
    yea ,ill try ..if not fu-ck it ill try to do better on my final
    peace out
  19. Jul 6, 2006 #18


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    And I honestly wish you the best of luck in becoming a good dentist. Physics might not be "your thing", but please stay open minded to any topics/subjects that might cross your path. It's a good approach for life in general and you don't want to miss the fun parts of it, right? :smile:


  20. Jul 6, 2006 #19
    kol 5ara

    thanx i will :)
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