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!

Hockey puck momentum problem

  1. Oct 7, 2008 #1
    1. The problem statement, all variables and given/known data
    A hockey puck moving at 0.43 m/s collides elastically with another puck that was at rest. The pucks have equal mass. The first puck is deflected 35° to the right and moves off at 0.36 m/s. Find the speed and direction of the second puck after the collision.

    2. Relevant equations
    1/2mv2 + 1/2mv2 = 1/2mv2 + 1/2mv2
    momentum initial = momentum final

    3. The attempt at a solution
    no idea
  2. jcsd
  3. Oct 7, 2008 #2


    User Avatar
    Homework Helper

    Start by putting the equations for initial momentum and final momentum.

    [tex] m \vec{v_{1}} + m \vec{0} = m \vec{v_{1}}' + m \vec{v_{2}}' [/tex]

    then set up the KE equations too
  4. Oct 7, 2008 #3


    User Avatar
    Homework Helper

    This would be an elastic collision.

    You would want to focus on the conservation of momentum, not the conservation of energy.

    In this regard you need to identify the components of the x,y velocity and add them separately to determine the components of the one you don't know. Then recombine the components to give the right answer.
  5. Oct 7, 2008 #4
    uhhh i'm bad at physics can you elaborate?
  6. Oct 7, 2008 #5


    User Avatar
    Homework Helper


    are you familiar with vectors?

    the problem basically is

    [tex] v_{1} \vec{i} + \vec{0} = v_{1}_{x}' \vec{i} + v_{1}_{y}' \vec{j} + v_{2}_{x}' \vec{i} + v_{2}_{y}' \vec{j} [/tex]
  7. Oct 8, 2008 #6

    I see that Mass X Velocity initial1 + Mass X Velocity initial2 = Mass X Velocity Final1 + Mass X Velocity Final2.

    nevermind, i figured out how to do the problem, thanks.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Hockey puck momentum problem
  1. Hockey Puck problem (Replies: 2)

  2. Hockey Puck (Momentum) (Replies: 1)