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!

Homework Help: Apply conservation of momentum to the collision

  1. Nov 28, 2007 #1


    User Avatar
    Gold Member

    1. The problem statement, all variables and given/known data

    2 automobiles of equal mass approach an intersection. One vehicle is traveling with a velocity of 13.0m/s toward east and other is traveling north with a speed of [tex] v_2i [/tex]. The vehicles collide at the intersection become stuck together and leave parallel skid lines at an angle of 55.0 deg north of east. Speed limit for both cars is 35mi/h and the driver of th northward moving vehicle claims he was within speed limit when it occured. Is he telling truth?

    2. Relevant equations

    3. The attempt at a solution

    I don't have the masses so how do I do this problem??

    I don't have the v2 so I assume I could work with 35mph speed as the initial speed of the other vehicle but other than that I'm not sure what to do... and I don't have final vf after collison

    35mph=> 15.646m/s

    Last edited: Nov 28, 2007
  2. jcsd
  3. Nov 28, 2007 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Call the mass of each car "m". You won't need the actual value.

    Apply conservation of momentum to the collision. Set up two equations, one for the x-components (East) and one for the y-components (North). Call the final speed vf.

    You should be able to solve for v2.
  4. Nov 28, 2007 #3


    User Avatar
    Gold Member

    Thank You Doc Al

    I got it.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook