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 Collision

  1. Feb 12, 2009 #1
    One hockey puck of mass 0.1 kg strikes an identical stationary puck on a frictionless ice rink. If the first puck had a velocity V(0)=3.8m/s before the collision and v(1)=0.8 m/s after in the same direction, what fraction of the energy was lost?
    Where do I even start to find the answer??
  2. jcsd
  3. Feb 12, 2009 #2
    If the rink is frictionless, then no energy should be lost. This is a momentum problem, and momentum is a conserved quantity. Is this your question, or are you trying to find the fraction of energy lost in the first puck as opposed to the fraction of energy lost of the system?
  4. Feb 12, 2009 #3
    I would assume the question is asking how much energy was lost by the first puck.

    That's a simple matter of taking the energy before and after via E=1/2mv2

    The difference would be the energy lost by the first puck.
  5. Feb 12, 2009 #4
    If you are indeed talking about the energy lost by the first puck then dantose is correct.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook