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: Friction with block on incline

  1. Feb 19, 2008 #1
    Hello, this is a physics problem I worked out an cannot determine what I did wrong.
    Attached is the problem and my solution. Any help would be very appreciated.

    1. The problem statement, all variables and given/known data

    2. Relevant equations

    F = ma, f_k = Mu_k * N, dx = v0t + 1/2at^2

    3. The attempt at a solution

    Attached Files:

  2. jcsd
  3. Feb 19, 2008 #2
  4. Feb 19, 2008 #3

    Doc Al

    User Avatar

    Staff: Mentor

    Looks to me that you assumed the force of the rope on the mass was equal to the weight of the hanging mass. That's not true. (If it were true, the hanging mass would be in equilibrium.)

    Instead, call the rope tension T. Apply Newton's 2nd law to both masses, then combine the equations to solve for the acceleration.
  5. Feb 19, 2008 #4
    Ooooh yeah. Thanks!
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook