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Homework Help: Collision in 2 dimensions (Momentum)

  1. Jan 20, 2007 #1
    1. The problem statement, all variables and given/known data
    Two spacecrafts have linked in space and are coasting with their engines off, heading directly towards Mars. The spacecrafts are thrust apart by large springs. Spacecraft 1 with mass of 1.9 x 10^4 kg, then has a velocity of 3.5 x 10^3 km/h at 5.1 degrees to its original direction. Spacecraft 2 with mass 1.7 x 10^4 kg, has then a velocity of 3.4 x 10^3 km/h at 5.9 degrees to its original direction. Determine the original speed of the two craft when they were linked together.

    2. The attempt at a solution
    Please see attached my attempt to solve this question. Am I on the right path? Do I have to calculate for Y axis too? Many thanks

    Attached Files:

    Last edited: Jan 20, 2007
  2. jcsd
  3. Jan 20, 2007 #2

    So Basically, I know now that the force of the spring is in fact internal. But, if there is no velocity on the y axis why would I have to calculate it? And I on the right path performing calculations for the x axis only?

  4. Jan 20, 2007 #3
    You are indeed. The work done by the spring only acts in a Y direction so because of that, there is no change in speed in the x direction.
  5. Jan 20, 2007 #4
    awesomeness.... thank you
  6. Feb 17, 2007 #5
    From looking at your work, you forgot to convert the speeds from Km/h into m/s before plugging the numbers into the equation.
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