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!

Did i rearrange this equation correctly? (circular motion)

  1. Dec 7, 2013 #1
    d1. The problem statement, all variables and given/known data A bucket 2.00kg is whirled in a vertical circle of a radius 1.10m. At the lowest point of its motion the tension in the rope supporting the bucket is 25.0 N a) find the speed of the bucket b) how fast must the bucket move at the top of the circle so that the rope does not go slack?



    2. Relevant equations v=√gr , FT = -mv2/r + mg ,

    g=9.81m/s^2
    m=2.00kg
    r=1.10m
    FT= 25.0 N


    3. The attempt at a solution a) v=√rg = √1.10m x 9.81m/2^s = 3.28m/s

    b) v=√FTr-mg/-m <----- Im not sure if i rearranged that correctly
     
  2. jcsd
  3. Dec 7, 2013 #2
    Maybe you should show the steps in how you rearranged it. Go through every step, and you will see, that it is wrong.
     
  4. Dec 7, 2013 #3
    can you show the correct equation to find v?
     
  5. Dec 7, 2013 #4
    FT = -mv^2/r + mg
    FT - mg = -mv^2
    (FT - mg)*r/m = -v^2
    -(FT - mg)*r/m = v^2

    v = sqrt(-(FT - mg)*r/m)
    v = sqrt((mg*r - FT*r)/m)
     
  6. Dec 7, 2013 #5
    Although I don't think that is the correct method for this problem, anyway. I didn't look too much into it, though, but I am guessing, you will get some complex number from this.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Did i rearrange this equation correctly? (circular motion)
  1. Did i do this correctly (Replies: 11)

Loading...