1. Not finding help here? Sign up for a free 30min 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!

Starting to forget my physics: silly energy question

  1. Aug 21, 2005 #1
    if two equal masses with equal speed are traveling towards eachother, do they have 0 total energy, or twice the energy of one mass?
    I know they will have 0 total momemtum, but I can't remeber if adding their energy is a vector thing or not.
  2. jcsd
  3. Aug 21, 2005 #2


    User Avatar
    Gold Member

    Its not a vector problem and how can they have 0 momentum if they are both in motion.
  4. Aug 21, 2005 #3
    If they are considered as a system then the system has zero net momentum. Each individual component has its own momentum vector according to its path. Their kinetic energy is the sum of the kinetic energies of each piece, KE is a scalar and not a vector.
  5. Aug 21, 2005 #4
    ok, thats what i was thinking but wasn't positive.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Starting to forget my physics: silly energy question