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!

San Francisco YoYo

  1. Mar 25, 2014 #1
    1. The problem statement, all variables and given/known data
    A large yo-yo is released from a crane over San Francisco Bay. The 129 kg yo-yo consists of two uniform disks of radius 30 cm connected by an axle of radius 3.2 cm.
    (a) What is the magnitude of the acceleration of the yo-yo during its fall?
    (b) What is the magnitude of the acceleration of the yo-yo during its rise?
    (c) What is the tension in the cord on which it rolls?
    Hint: Use the equation for rolling down a ramp.


    2. Relevant equations
    a= -g/(1+I/mr^2) is the equation it is referring to
    For a disk, I=(mr^2)/2

    3. The attempt at a solution
    I'm stuck at finding I. I would apply the disk equation to each of the three disks in the yoyo. But it doesn't divide the three disks into their individual masses, so I don't know how to find I.
    Parts A and B should be the same, correct?
    And to find tension, F(total)=ma=F(gravity)-F(tension)=mg-F(tension), so F(tension)=mg-ma correct?


    Update:
    Resolved myself....I don't really understand why this was correct but it was.
    I=((129 kg)(.3 m)^2)/2
     
    Last edited: Mar 25, 2014
  2. jcsd
  3. Mar 25, 2014 #2

    maajdl

    User Avatar
    Gold Member

    If you don't understand why, then it is not resolved!
    That's the right time to solve and learn.
     
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: San Francisco YoYo
  1. Yoyo problem (Replies: 1)

  2. Yoyo Problem (Replies: 27)

Loading...