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Homework Help: Momentum question

  1. Nov 18, 2004 #1
    I am desparate and only have 1 submission left on this question. Can someone help me with the answer please?
    8. [CJ5 7.P.032.] The drawing shows a collision between two pucks on an air-hockey table. Puck A has a mass of 0.020 kg and is moving along the x axis with a velocity of +5.5 m/s. It makes a collision with puck B, which has a mass of 0.040 kg and is initially at rest. After the collision, the two pucks fly apart with the angles shown in the drawing.

    Puck a goes into quadrant 1 at an angle of 65.
    Puck b goes into quadrant 4 at an angle of 37.


    Find the final speed of
    (a) puck A and
    m/s
    (b) puck B.
    m/s
     
  2. jcsd
  3. Nov 18, 2004 #2
    Hi Katerina,
    Use the vector equation of conservation of linear momentum.The motion in your problem is restricted to a plane so you need to deal with only x and y components of momentum.Steps involved:
    1) Choose your system such that total external forces along x and y directions is zero_Only then momentum will be conserved in these directions.The obvious choice is (A+B)
    2)Write the total momentum of your system before collision in x direction and equate it with the total momentum of the same system after collision in same direction.Repeat for y direction.
    Remember to take x and y components of final momenta as they are not strictly in x and y directions.
     
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