Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Need help with an angular momentum problem...

  1. Apr 21, 2018 #1
    1. The problem statement, all variables and given/known data
    I've spent at least 1.5 hours on this problem trying to figure out what i did wrong and I can't find anything. With an exam in two days plus another chapter to go through.

    Regardless, here are the problem(6) and answer, as well as my work. Hope you can read it, and the writing on the bottom left in red was just a variation of me using a negative value for m1(B/4) , as oppose to a positive like the right.

    2. Relevant equations / work

    problem and answer:




    Thank you very much

    Also, I'm new here so i don't know how embed images.



    Left side of board:

    Right side of board:

    Last edited: Apr 21, 2018
  2. jcsd
  3. Apr 21, 2018 #2


    User Avatar

    Staff: Mentor

    Welcome to the PF.

    You use the UPLOAD button in the lower right of the Edit window to upload a PDF or JPEG image. Your work is hard to read at that resolution, so you may want to take several pictures closer to your work to make it more clear. Normally we prefer that the work is typed into the PF, using the math symbols under the Sigma ∑ symbol in the toolbar at the top of the Edit window, or using LaTeX (see the tutorial under INFO, Help/How-To at the top of the page).
  4. Apr 21, 2018 #3
    Hopefully you can read it now? Sorry, my camera quality is just poor. But like I said, I feel like I "solved" it right conceptually, i feel like it might be somewhere in my work that's wrong. I know there shouldn't be any torque so angular momentum is conserved, which is why I said total initial momentum (I add the momentums of the separate ants together right) is equal to the total final momentum.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?