Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Energy a scalar

  1. Oct 29, 2013 #1
    I am having trouble understanding why energy is a scalar. (1/2 mv^2, mgh, 1/2kx^2, etc).
    Can someone just briefly hit over why? I tried asking a few people but I still don't get it. Thanks.
     
  2. jcsd
  3. Oct 29, 2013 #2

    A.T.

    User Avatar
    Science Advisor
    Gold Member

    Because that's what is conserved.
     
  4. Oct 29, 2013 #3

    kith

    User Avatar
    Science Advisor

    For every (continuous) symmetry a physical system inhibits, we have a conserved quantity. The translation invariance in 3 spatial directions leads to 3 momentum components which are conserved. The temporal translation invariance leads to energy conservation.

    In relativity, the 3-vector of momentum is combined with energy to form the 4-momentum.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Energy a scalar
  1. Work is scalar (Replies: 1)

  2. Work scalar ? (Replies: 11)

  3. Definition of a scalar (Replies: 1)

  4. Scalar waves (Replies: 8)

  5. Scalar and vect (Replies: 1)

Loading...