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Homework Help: Did I get this right? (collision in 2-d)

  1. Oct 23, 2008 #1
    1. The problem statement, all variables and given/known data

    2 birds of same mass swoop down on a mouse at an angle of 60 deg from horizontal with speed 30 m/s. They collide and stick together, what is their resultant speed?

    2. Relevant equations

    Conservation of momentum.

    3. The attempt at a solution

    This was just on a test I took and I got 26 m/s but I'm thinking it should be just 30 m/s down? Or is some velocity lost during the collision?
     
  2. jcsd
  3. Oct 23, 2008 #2

    tiny-tim

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    Hi drewdiddy! :smile:

    Momentum is always conserved in collisions (energy isn't).

    So your answer was right. :smile:
     
  4. Oct 23, 2008 #3
    So it should have been 30 m/s instead of the 26 that I wrote? :(
     
  5. Oct 23, 2008 #4

    tiny-tim

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    No, your answer was right

    momentum is a vector, so you added the two momentums by vector addition, and you got 26 (times 2m). :smile:
     
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