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!

Newtons 3rd Law

  1. Dec 2, 2009 #1
    1. The problem statement, all variables and given/known data

    Two masses are places in a frictionless pulley system. Solve for the acceleration and tension force. )its a pullz question and the mu=0.1

    2. Relevant equations
    So i know that Fg=MG
    Fnet=ma
    Ff=MFn
    How can i solve this question? how come Fnet=Ft came out of nowhere?


    3. The attempt at a solution
     
  2. jcsd
  3. Dec 2, 2009 #2
    This seems to be an Atwood machine problem, although I don't understand the last part of the problem statement.

    You will want to set up the equations of motion for each mass. For mass m(1):

    F1 = m(1)*a = T -m(1)*g = 0

    For m(2):

    F2 = m(2)*a = m(2)*g - T = 0

    To solve for tension, first solve the two equations for acceleration (a) and then set them equal to each other. Then solve for T. For acceleration, solve the equation for T and set them equal to each other. Then solve for a.
     
  4. Dec 2, 2009 #3
    well the mu is 0.1 and i dont know were did you get the m and t-m
     
  5. Dec 2, 2009 #4
    Here's where I'm getting confused. What is mu?
     
  6. Dec 2, 2009 #5
    well it looks like a U,its the coefficent of friction, its grade 11 physics
     
  7. Dec 2, 2009 #6
    But you said the system was frictionless.
     
  8. Dec 2, 2009 #7
    shoot, my bad i was looking at the wrong question. sorry
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Newtons 3rd Law
  1. Newtons 3rd law (Replies: 3)

  2. Newton's 3rd Law (Replies: 1)

Loading...