1. Not finding help here? Sign up for a free 30min 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!

Momentum and Impulse. find final velocity!

  1. Jan 9, 2010 #1
    1. The problem statement, all variables and given/known data
    A 0.10-kg object moving initially with a velocity of 0.20 m/s eastward makes an elastic head-on collision with a 0.15-kg object initially at rest. What is the final velocity of the .10 kg object after the collision ?


    2. Relevant equations

    im not sure which equation to use :/

    3. The attempt at a solution

    i tried using m1v1+m2v2=(m1+m2) V
    but it didnt come out right.

    and i know the answer is -0.045 m/s
     
  2. jcsd
  3. Jan 9, 2010 #2

    rl.bhat

    User Avatar
    Homework Helper

    Hi maxjohnfresh, welcome to PF.
    i tried using m1v1+m2v2=(m1+m2) V
    This formula is true if both objects move together after collision.
    So use the formula
    m1v1i+m2v2i=(m1v1f+m2v2f) .
    Apply the conservation of energy and solve for v1f and v2f.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook