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: Elastic Collisions in One Dimension

  1. Oct 13, 2009 #1
    1. The problem statement, all variables and given/known data
    A cart with mass 310 g moving on a frictionless linear air track at an initial speed of 1.4 m/s undergoes an elastic collision with an initially stationary cart of unknown mass. After the collision, the first cart continues in its original direction at 0.64 m/s.

    2. Relevant equations

    (1/2)m1vo^2 +(1/2)m2vo^2 = (1/2)m1vf^2 + (1/2)m2vf^2

    3. The attempt at a solution

    (310)(1.4)^2 + 0 = (310)(.64)^2 + m2vf^2

    (310)(1.4)^2 - (310)(.64)^2 = m2vf^2

    but I feel like I need vf to find m2 so how am I supposed to go from here?
  2. jcsd
  3. Oct 13, 2009 #2


    User Avatar
    Homework Helper

    Two things have to be conserved in an elastic collision. One is energy, which you have. What's the other one?
  4. Oct 13, 2009 #3
    And momentum
    which would be

    m1v1o = m1v1f + m2v2f ???
  5. Oct 29, 2009 #4
    you sure it didnt say "inelastic" instead? and what exactly are they asking you to work out : /
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook