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 setting up basic dynamics problem

  1. Sep 13, 2005 #1
    http://fletchowns.net/incoming/picture.jpg [Broken]

    point a oscillates with accel of a=2880-144x. Magnitude of velocity is 11in/s when x=20.4in. Determine the max velocity of A & two positions at which velocity is zero.

    Why am I getting this wrong :( It seems so easy

    integrate a=2880-144x to get v, plug in 11in/s and 20.4in as the initial values, solve for the constant and you get the velocity equation. From the acceleration equation you know there is a critical value at x=20in, so plugging x=20 to the velocity equation should give you the max velocity, and the other part is just finding the zeroes of v=...is that the right setup?
    Last edited by a moderator: May 2, 2017
  2. jcsd
  3. Sep 13, 2005 #2


    User Avatar
    Homework Helper

    Your initial value (v=11in/s) is NOT QUITE at maximum-velocity
    location, so if you did not include a phase angle or time-offset,
    (ending up with 20.917...) that might be your error.

    umm, how do you know you're getting it wrong?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook