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!

Achieve a state of static equilibrium

  1. Mar 25, 2012 #1
    1. The problem statement, all variables and given/known data
    If a body is acted upon by clockwise moments of 75 N at 1.25 m
    And anticlockwise moments of 50 N at 1.3 m ,
    Is it in a state of static equilibrium ?
    If not what is required to achieve a state of static equilibrium ?


    2. Relevant equations
    sum of all forces on all particles of the system is zero ...


    3. The attempt at a solution
    Should I increase the 50 N to be 75 N , Then level the distance to get the equilibrium ?
    I really don't know What/How to solve this , Please guide me through ,
    Your helping efforts are Highly needed and appreciated .
     
  2. jcsd
  3. Mar 25, 2012 #2
    That is one way, but i think the idea is to calculate the torque needed to obtain equilibrium, and since they act from different distances you would write something like:
    [itex]\sum\tau = l_1f_1 - l_2f_2 = 0[/itex]
    and that is the condition /equation you need to solve it.
     
  4. Mar 25, 2012 #3
    I don't get these symbols ? more HELP please
    Please consider that I know so little, Teach me like a kid
     
  5. Mar 25, 2012 #4

    FeDeX_LaTeX

    User Avatar
    Gold Member

    Do you know how to calculate a moment?
     
  6. Mar 25, 2012 #5
    is it force x given distance ?
    in the question it would be
    75 N X 1.25 m
    ?
     
  7. Mar 25, 2012 #6

    FeDeX_LaTeX

    User Avatar
    Gold Member

    Yes. The moment about a given point is the size of the force x the perpendicular distance to that point.

    What do you know about the sum of the moments of the forces of a system that is in equilibrium?
     
  8. Mar 25, 2012 #7
    What is your point ?
     
  9. Mar 26, 2012 #8
    Answer
    - No it’s not in a state of static equilibrium,
    In order for a body to be in static equilibrium
    The vector sum of the forces and torques should be zero
    Moments:
    Moment = force × distance
    Clockwise=
    75N × 1.25m = 93.75 Nm .
    Anticlockwise=
    50N × 1.3m = 65 Nm.
    Total moments= 93.75 – 65 = 28.75 N clockwise direction
    so clearly it’s not in a state of static equilibrium,
    If the perpendicular distance of the anticlockwise moment was changed to 1.875m we would then get
    50N x 1.875 = 93.75
    75N x 1.25 = 93. 75
    We now have it in a state of static equilibrium.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Achieve a state of static equilibrium
  1. Static Equilibrium (Replies: 5)

  2. Static Equilibrium (Replies: 4)

  3. Static equilibrium (Replies: 2)

  4. Static Equilibrium (Replies: 5)

Loading...