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

Why do we make such

  1. May 9, 2004 #1

    JasonRox

    User Avatar
    Homework Helper
    Gold Member

    Why do we make such a careful distinction between gravitational mass and inertial mass, rather that talking about one mass only, since they are equivalent?
     
  2. jcsd
  3. May 9, 2004 #2

    selfAdjoint

    User Avatar
    Staff Emeritus
    Gold Member
    Dearly Missed

    There is no apparent reason why they should be equal in classical physics. The fact that they are equal requires explanation.
     
  4. May 9, 2004 #3

    JasonRox

    User Avatar
    Homework Helper
    Gold Member

    This is a question in the book. Practice question so it's not worth marks. I personally thought they are different, and that gravitational mass is a direct result from inertial mass.

    Is that right?

    Another question... I've been pondering this one.

    Let's say we have they train cars. They say that the first couplings have more force exerted on them than the last one.

    If they are moving at a constant velocity, and we ignore friction, would they have all equal forces of 0.

    According to Newton's Laws, they will continue on forever. If one had to snap, which is impossible, it would be impossible to predict on top of that.
     
  5. May 10, 2004 #4
    I could be wrong about this, but I am under the impression that acceleration does not increase gravitational mass of the object, only it's inertial mass.
     
  6. May 11, 2004 #5

    jcsd

    User Avatar
    Science Advisor
    Gold Member

    Think about a collsion between two charged objects compared to a collison between two objects with no charge.

    Pallidin in relativity the inertial mass and the gravitational mass are one in the same.
     
  7. May 11, 2004 #6
    So, the gravitational field coming from a given object is increased by acceleration? Thus, would a finely balanced, perimeter weighted gyroscope, having a rest weight of "x" actually weigh slightly more when accelerated?
     
  8. May 11, 2004 #7

    robphy

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Why do we make such
  1. Why do we have mass? (Replies: 13)

  2. Why do we feel this? (Replies: 2)

Loading...