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Homework Help: Bullet hitting a block

  1. Oct 12, 2009 #1
    1. The problem statement, all variables and given/known data
    An 8.37g bullet is fired into a 235g block that is initially at rest at the edge of a table of h = 1.18 m height (see the figure below).


    The bullet remains in the block, and after the impact the block lands d = 1.82 m from the bottom of the table. Determine the initial speed of the bullet.

    2. Relevant equations

    V = ((m + M)/m)*(2gh)^(1/2)

    v = velocity
    m = mass of bullet
    M = mass of box
    g = gravity
    h = height

    3. The attempt at a solution

    Not sure if the above equation should be used or not but it is all I have been working with. However, I am a bit lost as to how to solve this problem. Any assistance or suggestions would be greatly appreciated. Thanks.

    Last edited by a moderator: Apr 24, 2017
  2. jcsd
  3. Oct 12, 2009 #2


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    Homework Helper

    Try writing out the conservation of momentum equation of the bullet-block system. Then, write out d (=1.82 m) in terms of the initial speed and the table's height. Solve the system of equations.
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