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Ms.bio Group Title

I know its physics but can someone help me out on this? Please...What is the resultant momentum of a system of two particles with these masses and velocities: 3.75kg m/s moving North and 4.2 kg moving Northwest at 2.3 m/s?

  • 3 years ago
  • 3 years ago

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  1. zer0net Group Title
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    is the 3.75kg also traveling at 3.75m/s?

    • 3 years ago
  2. Ms.bio Group Title
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    wait I forgot...3.75 is moving at 5.6 m/s

    • 3 years ago
  3. dmancine Group Title
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    I don't totally understand the concept of the question, but it might just be that you need to add the two momentum vectors together. Step 1: draw a picture|dw:1318046019675:dw|

    • 3 years ago
  4. dmancine Group Title
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    Now calculate the momemtum vectors.|dw:1318046160525:dw| Now add the two vectors.

    • 3 years ago
  5. zer0net Group Title
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    p=mv P1=3.75*5.6=21N P2=4.2*2.3=9.66NW since its NW you know its 45degrees, so find normal vectors at that angle 9.66cos45 = 5.07 (i dont have calc) so your momentum will be 21N+5.07N = 26.07N

    • 3 years ago
  6. Ms.bio Group Title
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    yes i need to add the momentum together but i can't get how. I thought I have to use law of sines and cosines but I am not confident dealing with it.

    • 3 years ago
  7. zer0net Group Title
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    or you can also calculate NW vector based on your N vector and have a resulting momentum in direction of NW rather than N, however both answers should be correct.

    • 3 years ago
  8. dmancine Group Title
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    To add vectors together they need to be in rectangular form, not polar form. If you have a vector in polar form as (r, theta), then its rectangular coordinates are (r cos(theta), r sin(theta)).

    • 3 years ago
  9. zer0net Group Title
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    still confused?

    • 3 years ago
  10. dmancine Group Title
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    You said you got: In respect to the other post I used Law of Sines and Cosines and got an answer of 17.26kgm/s at 35.45 degree Nof W

    • 3 years ago
  11. dmancine Group Title
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    |dw:1318053871126:dw| When you add vectors together, the result will be the diagonal of the parallelogram they create. So, the result has to be between the two vectors. Where is your answer vector pointing?

    • 3 years ago
  12. Annand Group Title
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    Let P=9.66 Q=21 x=angle between the vectors which is 45 then magnitude of resultant is \[R=\sqrt{P^2+Q^2+2PQcos(x)}\]

    • 3 years ago
  13. Annand Group Title
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    |dw:1318072907791:dw|

    • 3 years ago
  14. Annand Group Title
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    and angle with respect to N-direction can be obtained from: \[R\times\cos\theta=Q+P\times\cos45\]

    • 3 years ago
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