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Velocity of a bullet

  1. Nov 7, 2009 #1
    1. The problem statement, all variables and given/known data Hey guys here is my problem:
    A bullet is fired horizontally into a wood block attached to a string,the bullet sticks in the block.Calculate the velocity of the bullet if the impact causes the block to swing 10cm above its initial level. Bullet=15g, Block=3kg,Height=10cm.

    . Relevant equations]
    Square root of 2gh (were g is acceleration due to gravity,h is height. j
     
  2. jcsd
  3. Nov 7, 2009 #2

    tiny-tim

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    Welcome to PF!

    Hi kubombelar! Welcome to PF! :smile:

    Start by using energy to find the initial velocity of the block.

    Then use conservation of momentum. :wink:
     
  4. Nov 7, 2009 #3
    Hey thanks. using the formula i stated,i found 14.1ms and 1.4ms if i convert cm to m. Am i correct?
     
  5. Nov 7, 2009 #4

    tiny-tim

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    Hi kubombelar! :smile:

    (what figure are you using for g?)
    That's a weird way of putting it. :confused:

    They can't both be correct, can they?

    So which is it? :smile:
    (and what do you then get for the velocity of the bullet?)
     
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