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!

Find the pebble's position, velocity, and acceleration

  1. Nov 28, 2007 #1
    A tire rolls in a straight line without slipping. Its center moves with constant speed [tex] V [/tex]. A small pebble lodged in the read of the tire touches the road at [tex] t = 0 [/tex]. Find the pebble's position, velocity, and acceleration as functions of time.

    So [tex] \bold{v} = \dot{r} \bold{\hat{r}} + r \theta \bold{\hat{\theta}} [/tex].

    Would it just be [tex] \bold{v} = V \bold{\hat{r}} + Vt \omega \bold{\hat{\theta}} [/tex] and [tex] \bold{a} = -Vt \omega^{2} \bold{\hat{r}} + 2V \omega \bold{\hat{\theta}} [/tex]?

    Then to find the position as a function of time, integrate the velocity?

    Last edited: Nov 28, 2007
  2. jcsd
  3. Nov 28, 2007 #2


    User Avatar
    Science Advisor

    You need to do this in cartesian coords, because the center keeps moving.
  4. Nov 28, 2007 #3
    So use the transformations [tex] x = r \cos \theta [/tex], [tex] y = r \sin \theta [/tex]?
  5. Feb 1, 2008 #4
    I had to do a problem similar to this, and I still don't understand it....
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook