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Homework Help: Question on acceleration and string-HELP

  1. Oct 5, 2006 #1
    I need big help on this question guys:

    One test for the effects of the acceleration of gravity is to tie a set of weights to a string, with the second lowest searated from the lowes by L0, the third lowest from the second lowest by L1, and so forth, and to then drop the string. Suposing that free fall corresponds to motion with constant acceleration, how would separations L1, L2,...,Ln (where n is the number of weights) be related to L0 if the sounds made by the weights as they land form a steady beat? The lowest weight starts at the surface onto which the other weights fall.

    If you can also explain me in to more detail so I can get it easily.
  2. jcsd
  3. Oct 5, 2006 #2


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    Staff: Mentor

    Since the acceleration of gravity is constant, what is the difference between having strings between the objects, and having rigid poles? Is there any difference? If not, why not?

    What is the kinematic equation that relates the acceleration of an object to its velocity and position?
  4. Oct 6, 2006 #3
    I still don't get it. Can you explain the question in detail. Can you guys please give me more hints if possible. PLEASE
  5. Oct 6, 2006 #4


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    Staff Emeritus
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    MASSIVE HINT: Is the distance between the weights going to change? Note that as berkeman said, the acceleration experienced by each object is constant and equal. Note also that all the weights begin from rest (vi=0) and the bottom weight starts on the surface (x0=0)
  6. Oct 6, 2006 #5
    What happens if you have four weights separated by strings of equal length on a horizontal surface, and then push them together at a constant speed (i.e., no acceleration)? You get Hup two three four, or BONG BONG BONG BONG, equally spaced sounds. This is related to the equation of motion for constant velocity and distance: x = vt.

    What is the equivalent equation of motion for constant acceleration, and how does this change the situation for the four weights?

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