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Homework Help: Conservation Of Energy

  1. Dec 15, 2016 #1
    • Member advised to use the homework template for posts in the homework sections of PF.

    I'm having promblem with b. I checked the solution, but I did'nt understand the logic.

    Kf+Ugf+Usf = Ki+Ugi+Usi

    Usf= 0, Ki=0, Ugf= 0

    I understand the logic's why they are equal to 0.

    I don't understand why final potential of spring (Usf) is equal to zero?


    Now, I got it. I read the problem in detail.
  2. jcsd
  3. Dec 15, 2016 #2
    The potential energy that is stored in a spring depends on how far something is compressing or stretching the spring. So in b, when the object is at the bottom of the incline, it is no longer in contact with the spring, meaning it cannot be compressing the spring. since it is not compressing the spring that means there is no energy stored in it.
  4. Dec 15, 2016 #3
    Thank you so much, I see it after posting thread.
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