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: Pully Problem, Force/Tension

  1. Sep 22, 2004 #1
    Ok I've been working on this problem for a while, and I'm kinda new to physics, so bear with me. So here it is:

    Heres the picture of the problem:

    prob68_Atwood1.gif


    A frictionless pulley with zero mass is attached to the ceiling, in a gravity field of 9.81 m/s2. Mass M2=0.150 kg is being accelerated downward with a=1.10 m/s2. Calculate the mass m1.

    Just assume there is no compression/stretching of the rope on this problem. ALso, I guess the acceleration of M1 would be -1.10 m/s^2, correct? Beyond this I'm really confused. Any help would be greatly appreciated! Thanks.

    Steven
     
  2. jcsd
  3. Sep 22, 2004 #2
    I suspect a/g = (M2- M1) / (M2 + M1). Then (M2 + M1) a/g = M2 - M1 . and
    M1 a/g + M1 = M2 -M2 a/g so M1 = M2 (1-a/g)/(1+a/g) .
     
  4. Sep 22, 2004 #3
    I'll see what kind of numbers I get with that, thanks!

    Edit: Hey looks like that worked out, thanks man! :biggrin:
     
    Last edited: Sep 22, 2004
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook