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Homework Help: Acceleration vectors

  1. Nov 10, 2004 #1
    I need to draw the acceleration vectors for the following diagram:
    http://home.earthlink.net/~urban-xrisis/phy001.gif [Broken]

    The velocity is constant.
    I have already got some, but what if the acceleration constant? Like when the car is going straight without turning?
    Last edited by a moderator: May 1, 2017
  2. jcsd
  3. Nov 10, 2004 #2
    well, what direction is the acceleration toward on the straight aways? what direction is the acceleration on the corner's.

    if that is your velocity on the corner's, i think you're mistaken. the velocity is tangential to the curve in uniform circular motion. this means that your velocity at the very edge of the circle is directed down and up.

    think about the momentum principle

    dp = Fnet * dt

    with both vectors, it's saying that the change in momentum, or acceleration, is pointing the same direction that the force is pointing.

    i hope that helps and i addressed the right issue correctly!
  4. Nov 10, 2004 #3
    I'm not quite sure I understand what you're saying. I know that the velocity vector is tangent to the circle, but I'm looking for acceleration vectors. On the circle, the acceleration is inwards, towards the center of the circle (centripetal acceleration). However, on the side where the car is going straight, there is not acceleration, the velocity is constant. So my question is, would there even be acceleration vectors at points 2 and 4?
  5. Nov 10, 2004 #4
    if there is no net force acting on the car (ie its not accelerating), then there is no change in momentum, thus no vector. point 2, to me, looks like it's part of the circular section. in that case i would think that the acceleration vector points towards the center of the semicircle.

    sorry, i thought you were saying those were velocity vectors that you had drawn in!

    edit: keep in mind that there are external forces working on the car, which you may or may not want to include in your system. if no force is applied by the car to the track, it will actually be accelerating in the negative direction.
    Last edited: Nov 10, 2004
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