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!

Avg and instantaneous accel question

  1. Sep 17, 2003 #1
    hello again,

    I am having trouble with this problem:

    A particle leaves the origin with an initial velocity v = (3.00i) m/s and a constant acceleration a = (-1.00i - 0.500j) m/s^2. When the particle reaches its max x coordinate, what are a)it's velocity and b) its position vector.

    Am I to assume that at the max the v = 0 m/s? That means I've got to assume that the motion is a parabola, but I don't think that I have enough information to assume that. Or do I? I would just like to know how to start this problem out. Can someone lead me in the right direction? Thanks!
  2. jcsd
  3. Sep 17, 2003 #2


    User Avatar

    I think considering at max x, the x component of v (but not neccessarily the y!) to be zero is pretty reasonable, as you are looking for turning points.
  4. Sep 18, 2003 #3


    User Avatar
    Staff Emeritus
    Science Advisor

    If v> 0 then the particle is still moving to the right: it's not yet at it's maximum x value.

    If v< 0 then is already moving to the left: it's coming back from it's maximum x value.

    In either case, the particle is not AT it's maximum x value.

    In order to be AT it's maximum x value, the particle's speed MUST be 0- that's not an "assumption"!
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Avg and instantaneous accel question