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!

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...