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: Another problem

  1. Feb 19, 2007 #1
    A sports car, picking up speed, passes between two markers in a time of 4.1s. The markers are separated by 120m. All the while, the car accelerates at 1.8m/s^2. What is its speed at the second marker?

    Here is what i did:

    d = vi(t)+1/2(a)t^2
    120=vi(4.1)+1/2(1.8)(4.1)^2
    29.3=vi+15.1
    vi=14.2m/s

    d=1/2(vi+vf)t
    120=1/2(14.2+vf)(4.1)
    vf=44.3m/s
    vf=25.2m/s
     
  2. jcsd
  3. Feb 19, 2007 #2

    radou

    User Avatar
    Homework Helper

    Your calculation is wrong. Check the numbers once again.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook