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!

How much torque must the pin exert to keep the rod from rotating?

  1. Mar 22, 2009 #1
    1. The problem statement, all variables and given/known data

    How much torque must the pin exert to keep the rod from rotating?
    (L=1.011m , M=3kg , m = .301kg)

    So I am guessing the point of rotation is the pin??
    But then how does the pin exert any torque if it is at the point of rotation?
    I'm not quite sure


    there is a sketch I've attached

    2. Relevant equations

    Ive used the equation [tex]\Sigma[/tex][tex]\tau[/tex]net=0=[tex]\tau[/tex]pin-[tex]\tau[/tex]M-[tex]\tau[/tex]m

    3. The attempt at a solution
    i have tried it so many ways and keep getting it wrong

    [tex]\tau[/tex]pin = 3kg*(1.011m/2) + .301kg*1.011m
    what am i doing wrong?
    Please help thankyou
     

    Attached Files:

    • M.doc
      M.doc
      File size:
      23 KB
      Views:
      72
    Last edited: Mar 22, 2009
  2. jcsd
  3. Mar 22, 2009 #2
    Re: torque

    For this type of problem, you probably don't need to worry about how the pin exerts a torque (though you can imagine in reality it would take a fair amount of force since there is only a small lever arm)

    It looks like you've neglected to calculate the force of each of the masses and are using the mass instead (kg*m is not the units of force)
     
  4. Mar 22, 2009 #3
    Re: torque

    yeah thank you i did forget to multiply by the acceleration constant g
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: How much torque must the pin exert to keep the rod from rotating?
  1. Torque in a rotating rod (Replies: 12)

Loading...