1. Limited time only! Sign up for a free 30min personal 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!

Car merging to main road: can it really be so simple?

  1. Oct 11, 2009 #1
    1. The problem statement, all variables and given/known data

    Upon merging from side to main road and starting from rest with a constant acceleration 3 m/s². At the exact time of our merging, another car is driving on the main road in the same direction with speed 50 km/h. At least how far behind us should the car be, if we don’t want it to catch up with us?

    2. Relevant equations

    v^2 = v0^2 + 2as
    s = (v^2 - v0^2) / 2a

    3. The attempt at a solution

    First I converted 50 km/h into 13.89 m/s.
    For initial velocity I took 0, because the car starts from rest. For velocity I took the velocity of the second car, which is 50km/h (13.89m/s).

    After plugging the numbers into the formula s = (v^2 - v0^2) / 2a, a got the result 4.38 m.
    Somehow the distance seems too small?! Were my calculations correct?
  2. jcsd
  3. Oct 11, 2009 #2


    User Avatar
    Science Advisor
    Homework Helper

    I think you made a typo on the caclulator
    s = 13.8^2 / 2*3 = 31.7m
  4. Oct 11, 2009 #3
    Thank you.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Car merging to main road: can it really be so simple?
  1. Car moving down road (Replies: 2)