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Homework Help: Conservation of momentum

  1. Dec 23, 2009 #1
    hi i am doing physics 30 by modules after doing it by class. and i am having a hard time working this question out.

    A car with a mass of 1400kg is westbound at 50km/h. it collides at an intersection with a northbound truck having a mass of 2000kg and travelling at 40km/h. what is the inital common velocity of the car and truck immediatley after the collision if they have an inelastic collision?

    i did all my conversions but i just cant figure out the proper steps in receiving the answer.
  2. jcsd
  3. Dec 23, 2009 #2
    Momentum should be conservered along both the x and y axes. Write some eqns to express the momenta before and after the collision--the mass of the car/truck is just the sum of the two individually.
  4. Dec 23, 2009 #3
    so i dont really have to worry about the inelastic collision.
    because i was stuck on that part.
    just go along with finding the inital momentum and final and go from there?
  5. Dec 23, 2009 #4
    Inelastic collisions only effect the conservation of kinetic energy, not momentum.
  6. Dec 24, 2009 #5


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