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

I Unit normal vector of a surface

  1. Jul 11, 2017 #1
    What is actually the unit normal vector of a surface?
    Is it this?
    34grrt2.png
    Or this one?
    2hwzpsh.png
    I see that those are opposite in direction. But, I want the correct one, which means that it should point outward.
    So, which one is correct?
     
  2. jcsd
  3. Jul 11, 2017 #2

    FactChecker

    User Avatar
    Science Advisor
    Gold Member

    Both are unit normals. The definition of "inward" and "outward" is dependent on an entire closed region whereas both gradient and cross product are local properties. The meaning of "outward" and can not be defined locally without reference to the larger context.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Unit normal vector of a surface
  1. Normal unit vector (Replies: 2)

Loading...