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: String Friction Question

  1. Sep 24, 2007 #1
    1. The problem statement, all variables and given/known data
    What concepts am I missing?

    A mass M is initially at rest on a horizontal surface, ms=0.30 and mk=0.20 . A horizontal string then pulls M with a tension T. Forces below are magnitudes.

    Correct Incorrect M will accelerate if T exceeds ukN
    Correct Incorrect N equals Mg
    Correct Incorrect M will accelerate if T exceed usN
    Correct Incorrect T equals usN if M remains at rest
    Correct Incorrect If M does not accelerate, then T less than or equal to usN
    Correct Incorrect The NET force on M (if M does not move) is ukN

    2. Relevant equations

    3. The attempt at a solution

    correct by exceeding the kinetice friction the mass will accelerate
    correct N and mg cancel on a level surface
    correct it will move from rest
    incorrect it could be lower than usN
    incorrect it would be true for ukn
  2. jcsd
  3. Sep 24, 2007 #2


    User Avatar
    Homework Helper

    I think you have everything right, except the first one...
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook