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!

Incline plane and pulley

  1. Nov 3, 2007 #1
    1. The problem statement, all variables and given/known data
    [​IMG]

    2. Relevant equations
    F = ma
    sohcahtoa

    3. The attempt at a solution
    The answer to the question is b, but I got a. I used the sine ratio and divided the forces that were acting on mass 1 by the forces acting on mass 2. Can someone help me on this question?
     
  2. jcsd
  3. Nov 3, 2007 #2

    Dick

    User Avatar
    Science Advisor
    Homework Helper

    That's because the question is so badly written. If you consider positive 'a' to be m2 accelerating down, then a) is correct. If you choose positive 'a' to mean m2 is accelerating up, then b) is correct.
     
  4. Nov 3, 2007 #3
    Actually, if you put it that way, I don't think that the question is worded badly, because m1g would be greater than the parallel force of gravity, so m2 would be accelerating up. Remember, m1 = m2. Can you explain in further detail how you came to your conclusion though?
     
  5. Nov 3, 2007 #4

    Dick

    User Avatar
    Science Advisor
    Homework Helper

    In working these problems, you get to choose which direction you consider positive. You chose a different and equally valid way to do that. The question should have been clearer on that.
     
    Last edited: Nov 3, 2007
  6. Nov 3, 2007 #5
    b) is correct.
     
  7. Nov 4, 2007 #6
    Can you show me how you got b?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Incline plane and pulley
Loading...