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!

Static friction between two objects.

  1. Mar 26, 2013 #1
    a child (m=30kg) sits 5m from the axis of rotation on a flat turn table which makes a full rotation every 8 seconds.

    A. find the childs period (t) and frequency (f)
    Full rotation every 8 seconds, T=8
    Frequency = inverse of period = 1/8

    B. What is the tangential velocity of the child?
    Vtan=ωR
    w=D(θ)/dt
    (2pi/8)*5= 3.926

    C. What is the centripetal acceleration of the child? what must the centripetal force acting on the child be?
    Acentripetd=v^2/R
    3.926^2/5=3.082
    F=ma
    30*3.082=92.48

    D. If this is the fastest the child can go without slipping off the turntable, determine the coefficient of friction between the child and the table surface.

    I cant figure out what equation to use.
    the only equations i have written down from class are
    Fs-maxs*FN
    Fkk*FN

    Any help would be great
     
    Last edited: Mar 26, 2013
  2. jcsd
  3. Mar 27, 2013 #2

    ehild

    User Avatar
    Homework Helper
    Gold Member

    Correct.

    If you want to keep 4 significant digits, round off properly.

    The force of static friction provides the centripetal force for motion along the circle. You are right, the maximum static friction is μsFN.

    What is N?

    ehild
     
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: Static friction between two objects.
Loading...