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: Finding coefficien of kinetic friction

  1. Oct 6, 2012 #1
    A slide loving pig slides down a 35 degree slide in twice the time it would taken to slide down a frictionless 35 degree slide. What is the coefficient of kinetic friction between the pig and slide?


    So with the frictionless slide I found ax=8.03m/s^2 but without velocity or the length of the slide I'm not sure how to find time. So i shifted to the slide with friction,

    Fy= n-mgsin(35)
    0=n-mgsin(35)
    N=mg sin(35)

    Fx=-fk+mgcos(35)
    Fx= mg(-╬╝ksin(35))+(cos(35))
    M*ax=^

    Ax=g(-╬╝ksin(35))+(cos(35))

    I definitely can't use the same value of acceleration right? Because the first acceleration assumed no opposing force.
     
  2. jcsd
  3. Oct 6, 2012 #2
    Pick an arbitrary length for the slide. You'll find that it'll cancel out of the equations. Use the time-distance formula for constant accelerations. Determine acceleration for each case first.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook