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!

Homework Help: Cetripetal and Centrifugal forces: points of action

  1. Dec 7, 2009 #1
    1. Do centripetal and centrifugal act on same body or on different bodies??
    I am told that if a stone tied to one end of the string is revolved around its another end(fixed), centripetal force acts on stone and centrifugal force acts on the fixed end of the string.

    3. The attempt at a solution

    I say both forces act on same body, centripetal provided by some another force and centrifugal due its own inertia.
    Which statement is true?? mine or the first one??
    Last edited: Dec 7, 2009
  2. jcsd
  3. Dec 8, 2009 #2
    Does anybody have any idea about this??
    please help....
  4. Dec 19, 2009 #3
    Please help........
  5. Dec 20, 2009 #4


    User Avatar
    Science Advisor

    Why in the world would you think this is a mathematics question? I am moving it to the physics homework section.
  6. Dec 20, 2009 #5


    User Avatar
    Science Advisor

    The first one. If you swing a stone one a string, centripetal force is the force, exerted by the string on the stone, that pulls it off a straight line. Centrifugal force is the name given to the feeling of a "fictitious" force your hand feels in exerting that centripetal force on the string.
  7. Dec 20, 2009 #6


    User Avatar
    Homework Helper

    Always forces appear in pairs. And they won't act on the same body.
    In the example of whirling stone, centripetal force, which acts towards the center, keeps the stone in the circular orbit by preventing it by going in a straight line path. Reaction to this force is experienced by the hand. It is away from the center. If you want you call it as centrifugal reaction. It is a real force. In this case there is no centrifugal force. Now, instead of whirling stone, consider a whirling bucket with some water in it. If the velocity of rotation is proper, the water does not spill out of the bucket even in the vertical circular motion. The force which keeps the water in the bucket is called centrifugal force. Water tries to move in a straight line path. But the bucket prevents it from doing so. When the bucket stops in the middle of the path, water spills out of the bucket. The force appears in the accelerated frame of reference.
  8. Jan 17, 2010 #7
    OKAY- got it
    Thank you
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook