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!

Antother Collision

  1. Nov 23, 2005 #1
    Antother Collision!!!!!!!!!

    A billiard ball moving with a speed of [tex]v = 2.2m/s[/tex] strikes an identical stationary ball a glancing blow. After the collision, one ball is found to be moving at a speed of [tex]v_2 = 1.1m/s[/tex] in a direction making a [tex] \theta = 60^o[/tex] angle with the original line of motion. Find the velocity of the other ball?

    I dont really know where to start...Maybe conserving momentum?
  2. jcsd
  3. Nov 23, 2005 #2
    Would I just do this:

    [tex]1/2m_1v_1_i^2 +1/2m_2v_2_i^2 = 2(1/2m_1v_1_f^2) + 1/2m_2v_2_f^2[/tex]

    since all of the masses are the same they cancel out and since the second ball is stationary..it is 0

    [tex]v_1_i^2 = 2v_1_f^2 + 2v_2_f^2[/tex]
    [tex]1/2(2.2)^2 = 2sin \theta(1.1)^2 + 2v_2_f^2[/tex]
    [tex]v_2_f = 1.53m/s[/tex]
  4. Nov 23, 2005 #3


    User Avatar
    Staff Emeritus
    Science Advisor

    Why is the kinetic energy term of m1 doubled on the right hand side?

    In an elastic collision, kinetic energy and momentum are conserved. Momentum is conserved in the x and y directions.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Antother Collision
  1. A collision (Replies: 2)