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: Atwoods Machine

  1. Jun 3, 2010 #1
    1. The problem statement, all variables and given/known data


    A frictionless, massless pulley is attached to the ceiling, in a gravity field of 9.81 m/s2.

    Mass M2 is greater than mass m1. The quantities T1, T2, T3 and g are magnitudes.

    3. The attempt at a solution


    The Options are Greater than, Less than, Equal To
    T1 is _____ m1g.(Greater than)
    The magnitude of the acceleration of M2 is _____ the magnitude of the acceleration on m1.(equal too)
    m1g + M2g is _____ T3(equal too)
    T1 + T2 is _____ T3.(greater than)
    T1 is _____ T2. (equal too)

    i donno what part im getting wrong.. any help?
     
  2. jcsd
  3. Jun 3, 2010 #2

    ehild

    User Avatar
    Homework Helper

    Show a picture. What are T1, T2, T3?
    If you have the picture, draw also the free-body diagram.

    ehild
     
  4. Jun 3, 2010 #3
    this question is pretty simple, T1 is the tension in the string attached to m1, T2 is the tension in the string attached to m2 and T3 is the tension in the string attached to the pulley.since m2 is greater hence it will fall down hence m1 will go up hence it can be deducted from here as m1 is going up hence net force on it is in upward direction hence t1 is greater than m1g....I think you can solve further but T1+T2 is not greater than T3 as the pulley is at rest hence net force on it is zero hence they are equal
     
    Last edited: Jun 3, 2010
  5. Jun 3, 2010 #4
    a few more of your answers are wrong try to make a proper free body diagram and take into consideration all the forces acting on each of the masses
     
  6. Jun 3, 2010 #5
    if you have problem solving these types of questions i recommend you study the textbook of physics by Resnick,Halliday and Walker
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook