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Homework Help: Car Truck Collisins w/ ANGLES

  1. Oct 7, 2011 #1
    Car Truck Collisins w/ ANGLES!!

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

    A blue car with mass mc = 431 kg is moving east with a speed of vc = 19 m/s and collides with a purple truck with mass mt = 1298 kg that is moving south with a speed of vt = 12 m/s . The two collide and lock together after the collision.



    2. Relevant equations
    What is the angle that the car-truck combination travel after the collision? (give your answer as an angle South of East


    3. The attempt at a solution

    I have no idea, something to do with adding the vectors. I just dont know how to incorporate the angle
     
  2. jcsd
  3. Oct 7, 2011 #2

    PeterO

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    Homework Helper

    Re: Car Truck Collisins w/ ANGLES!!

    You will be adding the momentum vectors - so start by using mass and velocity for each vehicle to get the momentum of each.

    NOTE: These questions are really frustrating in the masses used [not your fault].
    The minimum weight of a Formula 1 racing car [a glorified go-cart] is 640 kg. The idea of having a car of mass 431 kg is fanciful.
    A modern Small car has a mass around 1000 kg, and even a small truck will have a mass around 3000 kg.
     
  4. Oct 8, 2011 #3
    Re: Car Truck Collisins w/ ANGLES!!

    Which principle do you think we usually use in a collision problem?
     
  5. Oct 8, 2011 #4
    Re: Car Truck Collisins w/ ANGLES!!

    I'm assuming that was rhetorical. :P

    I think you should just find the resultant of the momentum vectors, and then arctan[(y-component)/(x-component)] (components of resultant) should give you the angle.
     
  6. Oct 8, 2011 #5
    Re: Car Truck Collisins w/ ANGLES!!

    I was encouraging the original poster to a better attemp!
     
  7. Oct 8, 2011 #6
    Re: Car Truck Collisins w/ ANGLES!!

    Right. Sorry.
     
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