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Homework Help: Physics homework-momentum and impulse-

  1. Apr 28, 2009 #1
    hello I'm struggling with physics this year at school i found this site looks great :smile: if this is a bad 1st post i wont be to surprised :biggrin: any way heres my problem...
    1. The problem statement, all variables and given/known data

    A Car A (with a mass of 750Kg) is travailing at 30 m s-1 and collides head on with car B travailing at 20 m s-1 with a (mass 1600kg) in the opposite direction

    2. Relevant equations
    A Calculate the magnitude of the momentum of each car before crashing

    B If the two cars lock together in the crash, in which direction will they be moving immediately after the collision?

    I Calculate the initial speed of the combined wreck immediately after the collision

    II why dose the speed quickly reduce to zero?

    3. The attempt at a solution

    .......ok so far i have drawn a picture like so...


    lol i have no idea...also i have the answerers in the back of the book but thats not learning so thats why i came here :)

    any help would be great! even if you could point me in the right direction

  2. jcsd
  3. Apr 28, 2009 #2


    User Avatar
    Homework Helper

    use the law of conservation of linear momentum. Since the two cars are moving in the opposite direction, you have to use proper sign for each momentum.
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