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!

Conservative force

  1. Dec 6, 2006 #1
    1. The problem statement, all variables and given/known data

    If a force on an object is always directed along a line from the object to a given point, and the magnitude of the force depends only on the distance of the object from the point, the force is said to be a central force. Show that any central force is a conservative force.

    2. Relevant equations



    3. The attempt at a solution

    i really dont have a clue....

    im guessing work done = force * distance

    and F = ma might be used but i dont know how!
     
  2. jcsd
  3. Dec 6, 2006 #2

    Hootenanny

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    What is the definition of a conservative force?
     
  4. Dec 6, 2006 #3
    that if you move an object around and place it back in its original position no energy is lost?
     
  5. Dec 6, 2006 #4

    Hootenanny

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Correct. Can you therefore write an expression for the work done by a central force?
     
  6. Dec 6, 2006 #5
    wd= ma * d ???
     
  7. Dec 6, 2006 #6

    Hootenanny

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Close but don't forget that the magnitude of the force is dependant on the displacement. Use vector notation for the displacement and write ma as F.
     
  8. Dec 6, 2006 #7
    does than not just give you wd = f* d

    im very confused about how to prove this!
     
  9. Dec 6, 2006 #8

    Hootenanny

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    No. Note that the magnitude of the force is a function of displacement and note that we are looking at displacement which is a vector quantity. Now, because the force is not constant (because is varies with displacement), we cannot use the simple relationship you outlined above. Do you know a general definition of the work done by a force (involving calculus)?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Conservative force
  1. Conservative FOrce (Replies: 7)

  2. Conservative forces? (Replies: 3)

Loading...