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: Car momentum question

  1. Sep 19, 2011 #1
    1. The problem statement, all variables and given/known data
    Two vehicles traveling as shown collide at an intersection and lock together. Car A ha sa mass of 1000 kg and was traveling east at 40 m/s. Car B has an unknown mass and was headed south at 15 m/s. If the wreckage skids exactly southeast just after the collision, then what is the mass of Car B. Also, what was the initial speed of the wreckage?

    2. Relevant equations
    Pti = Ptf

    3. The attempt at a solution
    The thing that is throwing me off with this question is the fact that Car B is of unknown mass. I tried to do trigonometry using the two vectors given, 4000 kg(m/s) [E] and (x)(15 m/s) , but I couldn't seem to work out an answer.
    Last edited: Sep 20, 2011
  2. jcsd
  3. Sep 20, 2011 #2


    User Avatar

    Staff: Mentor

    Momentum is a vector quantity. So addition of momentum of A plus momentum of B forms a closed triangle. You are told the angle/s.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook