1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: 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


    User Avatar
    Science Advisor
    Homework Helper

    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


    User Avatar
    Science Advisor
    Homework Helper

    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?)
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook