Hey there! Sign in to join this conversationNew here? Join for free

circular motion problem Watch

Announcements
    • Thread Starter
    Offline

    10
    ReputationRep:
    https://oxfordpat.wordpress.com/oxfo...2-question-17/

    how do I know that F is acting inwards rather than outwards? Also can someone explain the significant of the F greater than or equal to 0? I dont understand how it affects the object touching or not.
    Offline

    19
    ReputationRep:
    (Original post by alvan15)
    https://oxfordpat.wordpress.com/oxfo...2-question-17/

    how do I know that F is acting inwards rather than outwards? Also can someone explain the significant of the F greater than or equal to 0? I dont understand how it affects the object touching or not.
    F here means N, normal reaction from surface against object; it points inward. If you sum a set of forces, net inward result is called centripetal force (Fc).

    At T: N + mg = Fc = mv^2/r => N = m(v^2/r - g)

    N is ≥ 0 if object touches track, else it falls.
    KE = 0 at T => N < 0 => object falls vert (Ans B)
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    Break up or unrequited love?
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

    Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

    Quick reply
    Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.