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: Momentum and when V' is Zero

  1. May 6, 2009 #1
    1. The problem statement, all variables and given/known data

    Two balls roll directly towards eachother. The 0.25kg ball has a speed of 1.7m/s. The 0.18kg ball has speed of 2.5m/s. After the collision, the 0.25kg ball has reversed its direction and has a speed of 0.10m/s . What is the magnitude and direction of the 0.18 kg ball after hte collision?

    2. Relevant equations

    3. The attempt at a solution

    I know the answer.... IT's 0 m/s . Further question though:

    On a test, I'd be questioning that result. As I did when I first obtained it in the homework... So I thought to myself: Zero tends not to just come out of nowhere... There's usuall an indicator that it's coming. What is the indicator that one of the objects in a collision will stop? Is there any sort of indicator in this case?


  2. jcsd
  3. May 6, 2009 #2


    User Avatar
    Homework Helper
    Gold Member

    There's no special indicator in this case other than the momentum conservation calculation.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook