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Homework Help: Car Collision at an Angle

  1. Nov 6, 2006 #1
    Two cars, both of mass m, collide and stick together. Prior to the collision, one car had been traveling north at speed 2v, while the second was traveling at speed v at an angle phi south of east (as indicated in the figure). After the collision, the two-car system travels at speed v_final at an angle theta east of north.
     

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  2. jcsd
  3. Nov 6, 2006 #2
    Conservation of momentum, remember velocity is a vector quantity.

    Show your work so we can determine where you need help.
     
  4. Nov 27, 2006 #3
    can anyone help me with the above problem? i've been trying to work it out but i can't find the answer to vfinal.... or theta
     
  5. Nov 27, 2006 #4
    Like civil_dude said, show your work so we know where you went wrong.

    Either use the velocities as vectors or break the conservation of momentum into its x and y components.
     
  6. Nov 27, 2006 #5
    i got the other homework problems but i don't think i'm even close for this one. the answer that i have so far for vfinal i have sqrt( (v*cos(phi))^2 + (2v - vsin(phi)^2)

    but that doesn't work or feel right either. and i can't even begin to find theta
     
  7. Nov 27, 2006 #6
    Are you using energy conservation? The collision is inelastic. Use conservation of momentum.
     
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