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: Physics pulley question help please

  1. Apr 12, 2010 #1
    Diagram kkk.jpg

    1. The problem statement, all variables and given/known data
    Consider the two body system above. There is a 0.25kg object accelerating across a rough surface. The sliding object is attached by a string to a 0.1kg object which is suspended over a pulley. the coefficient of kinetic friction is 0.183. Calculate the acceleration of the block and the tension in the string.

    2. Relevant equations
    Fg=mg
    Fnet=ma


    3. The attempt at a solution

    i got the acceleration to be 1.5...m/s^2 i dont know if it is right

    fn=fg=mg 0.25 x9.81m/s^2 =2.4525N
    ff=ufn
    ff=0.183 x 2.4525N =0.4488075 ff=fg since fn=fg

    fg2= 0.1 x 9.81 =0.981 then subtracted them to get fnet then divided
     
  2. jcsd
  3. Apr 12, 2010 #2
    Let the driving force (weight of the hanging block-friction of the block on the surface)=the combined mass time acceleration. To solve for a.

    mg-Mgu=(m+M)a.

    The tension in the string should be the force required to drive the block on the surface against friction at a.

    T=Ma+Mgu.



    *or so I think, it's been a while since I have done such problems.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook