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: Will someone check my work to see if Im on the right track?

  1. Jul 22, 2013 #1
    This is collisions and momentum problem. for some reason it just seems like a short problem and im use to doing long problems so im here to check my work.

    the questions is

    A 50g bullet is fired vertically up at a 1.00 kg ballistic pendulum . The bullet strikes the block at
    1000 m/s and emerges from it at 800 m/s. How far does the block rise? Assume that the
    duration of the collision is instantaneous, in other words, during the collision no external forces
    were acting on the system

    my answer

    Impulse given to block=0.050x1000-0.500x800=10=change in the block's momentum=1.00xv→v=10m/s. Using v²=u²+2as with v=0, u=10, a=-g=-9.8, we get 0=100-2x9.8s→s=5.1m.
    [The collision isn't elastic but this doesn't matter since we aren't using energy conservation to solve the problem].

    Am i missing something else?
  2. jcsd
  3. Jul 22, 2013 #2


    User Avatar
    Science Advisor
    Homework Helper

    hi camel-man! :wink:
    looks ok to me :smile:

    (though that's not how a ballistic pendulum works :confused:)
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted