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!

Check work on kinematics problem

  1. Apr 27, 2012 #1
    1. The problem statement, all variables and given/known data
    A truck accelerates uniformly from rest to 48km/h in 20s, holds speed for 2 minutes, and then accelerates to 100km/h at a rate of 17m/s^2. How long does it take, from rest, to reach 100km/h and what distance it traveled in this time?


    The book says it takes 148.5s, and I keep getting 140.85s.
    For distance the book says 1904m, and I been getting lower at 950.57m.

    I was hoping someone could just check the answers for me, since I am doing a course from a book that has had alot of mistakes thus far, if it turns out that my answers are wrong I will post my what I've been doing to get some help on it. Thanks much!
     
  2. jcsd
  3. Apr 27, 2012 #2
    Hey Caperjay, could you post some work? Then we'll see what's up.
     
  4. Apr 27, 2012 #3
    Heres what I've done. For the total time I got 20s + 120s + (13.33=27.78 + 17m/s^2xt) where t turns out to be 0.85s, for a total of 140.85s.

    For total distance I've got (0+13.33)/2 x 20s + (13.33 + 13.33)/2 x 120s + (13.33 + 27.78)/2 x 0.85s, for a total of 950.57m.
     
  5. Apr 28, 2012 #4
    "at a rate of 17m/s^2"

    Mighty powerful truck!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Check work on kinematics problem
Loading...