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!

Yo-Yo Rotation

  1. Apr 27, 2009 #1
    1. The problem statement, all variables and given/known data

    A yo-yo has mass of 400 kg and radius of 1.5m. Its axle of rotation has a radius of 0.1m. Its string is attached to a crane. What is its final velocity after it is released.
    mass (m)=400 kg
    Radius (R)= 1.5 m
    axle of yo-yo (r)= 0.1 m
    height (h)=57m
    angular acceleration (x)= x

    2. Relevant equations

    F=ma; I=(1/2)mr^2; a=xr a/r=x



    3. The attempt at a solution

    F=ma ; Torque=Tr=Ix T=Ix/r

    Fnet,y = mg - T = ma

    mg - I(a/r)/r = ma

    mg = ma + I(a/r)/r

    mg/ (m + I/r^2) = a

    mg/(m + (1/2)mr^2/r^2 ) = a

    a = 6.53 m/s

    This doesnt seem right. Can anyone show me my error?
     
  2. jcsd
  3. Apr 27, 2009 #2
    well you have calculated the accelertion whereas the question asks for final velocity ...
     
  4. Apr 28, 2009 #3
    lol . ok figured it out. i was also using lowercase r instead of uppercase R.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Yo-Yo Rotation
  1. Rotation only of yo-yo (Replies: 1)

  2. Rotation: Yo-Yo (Replies: 1)

Loading...