1. Not finding help here? Sign up for a free 30min 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!

Physics 20, Friction.

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

    I need to find the coefficient of friction on a surface. Two weights were given, 0.5672kg and 0.050kg

    2. Relevant equations

    m1a + Mm1g = m2g - m2a

    3. The attempt at a solution

    (0.5672kg)a + M (0.5672)(9.81) = (0.050kg)(9.81) - (0.050kg) a


    M represents the coefficient of friction. I need to solve for that, I just don't know where to take it from here.
     
  2. jcsd
  3. Apr 1, 2009 #2

    mgb_phys

    User Avatar
    Science Advisor
    Homework Helper

    That's not enough of a question - what were the two weights doing?
     
  4. Apr 1, 2009 #3
    246t8h4.jpg

    That is what is happening
     
  5. Apr 1, 2009 #4

    mgb_phys

    User Avatar
    Science Advisor
    Homework Helper

    That helps.
    Now try drawing in the forces.
    The frictional force is = coeff_friction * normal force (ie weight)
     
  6. Apr 1, 2009 #5
    Can you explain that a little more please?
     
  7. Apr 1, 2009 #6

    mgb_phys

    User Avatar
    Science Advisor
    Homework Helper

    There is a force down on the 0.05kg mass = m g
    This same force pulls the larger mass to the right, so an equal friction force acts to the left (assuming no loss in the pulleys).
    The definition of coeeficient of friction is
    friction force = coeef * normal force

    The normal force is the force acting down on the suface = M g
     
    Last edited: Apr 2, 2009
  8. Apr 2, 2009 #7
    Ok thanks!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Physics 20, Friction.
  1. Physics 20-1: Energy (Replies: 3)

  2. Physics 20 (Replies: 2)

  3. Physics 20-1 Dynamics (Replies: 2)

Loading...