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Homework Help: Desperate and immediate help needed willing to pay

  1. Dec 12, 2005 #1
    I have a test tomarrow and My tutor did not show up at 9pm like he was supposed to.... I have been working as hard as we can to work out the problems but still have 4 that we have no clue how to even begin is there anyone on tonight who can help? Please IM me Quad150db at yahoo or AIM or post a reply in this thread hell send smoke signals I dont care how but please let me know.... Just so you know the class is phyiscs 1 college level... WILLING TO PAY!!
    http://img470.imageshack.us/img470/4411/question17wu.jpg [Broken]
    Last edited by a moderator: May 2, 2017
  2. jcsd
  3. Dec 12, 2005 #2
    Well, the first two problems involve conservation of energy and the second two involve conservation of momentum. In the first case you're exchanging gravitational potential energy for rotational kinetic energy, in the second case you're exchanging gravitational potential for kinetic energy in the vertical direction, for the third problem you have conservation of linear momentum and for the fourth it's conservation of angular momentum. In every case it's the same: you write down an expression for the initial ammount of the conserved quantity (energy or momentum), then an expression for the final ammount of the quantity and you solve for whatever variables are being asked for.

    I think that should get you started, if you still have questions be sure and post whatever work you've done so we can see what needs to be done next.
  4. Dec 12, 2005 #3


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    Homework Helper

    Some hints are given in the questions themselves. For the first question, you should apply the conservation of energy principle. What is lost in gravitational potential is gained in kinetic energy. At 15 degrees, what is the loss in height? mgh = 0.5mv^2.
  5. Dec 12, 2005 #4
    Thank you for that the problem is I live down in broward county My school was closed down for 3 and a half weeks after the hurricane and after reopening the teacher didnt want to fall behind and just told us that to that we would be responsible for the material for that period of time we were to use the book to "work it out" now the problem that I have it That I have NO idea what so ever on how to even start the equasions to solve these..:cry:
  6. Dec 12, 2005 #5
    That's a lot of material to cover on a message board. You need to know how to calculate gravitational (and possibly spring) potential energy, then linear and rotational kinetic energy, and you need to know how to calculate linear and rotational momentum. Once you know these you just need to calculate the values at the beginning and end of the situations and set them equal to eachother. You book should cover all of this.

    If you have specific questions on examples given in the book or the problems feel free to ask, but if you need instruction on how to deal with these things there's no better source than your text book.
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