Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Stuck on simple constant accel. problem

  1. Aug 28, 2011 #1
    1. An antelope moving with constant acceleration covers the distance between two points 70.0 meters apart in 7.00 seconds. It's speed as it passes the second point is 15 m/s.
    A] Find speed at first point. B] What is the acceleration?




    2.
    From text University Physics 11th edition question 2.21 page 70
    Eqns of motion with constant acceleration
    Vx=Vox+AxT
    X=Xo+VoxT+1/2AxT
    Vx2=Vox2+2Ax(X-Xo)
    X-Xo=((Vox+Vx)/2)T




    3. I have tried but nothing worth posting. I'm stuck on the fact that I cannot find how to use the average Velocity to find the instantaneous Velocity at point 1, Thank you!.
     
  2. jcsd
  3. Aug 28, 2011 #2

    lewando

    User Avatar
    Homework Helper
    Gold Member

    You know T, Vx, and (X - X0). One of the four equations will allow to to determine V0x directly.
     
  4. Aug 28, 2011 #3
    Crap! For some reason I was stuck on having to find the original velocity by finding the limit as time went down to zero.... So I was plugging in 0.01, 0.001 and was getting ridiculous answers. Thank you! I've posted one more problem I cannot seem to get my head around.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook